HEAT STROKE (AND ILLNESS) IS A MEDICAL EMERGENCY.
COOL FIRST, WHILE CALLING CALL 911, AND TRANSPORT SECOND.
REMOVE THE UNIFORM AND PLACE THE ATHLETE INTO A KIDDY POOL FULL OF ICE WATER INSTANTLY.
EVERYOUTDOOR PRACTICE AND GAME FIELD, DURING WARM WEATHER, SHOULD HAVE A KIDDY POOL (WALMART, COST ~ $50-75) STANDING BY WITH WATER HOSE AND LARGE FULL ICE CHEST READY TO POUR INTO POOL,
KENTUCKY MEDICAL ASSOCIATION / KENTUCKY HIGH SCHOOL ATHLETIC ASSOCIATION PROCEDURE FOR AVOIDING HEAT INJURY / ILLNESS THROUGH ANALYSIS OF HEAT INDEX AND
RESTRUCTURING OF ACTIVITIES
Complete listing of support documents available at http://www.khsaa.org/sportsmedicine/
“Following months of study, after one year of implementation and in an effort to help protect the health and safety of student-athletes participating in high school sports, the Kentucky Medical Association Committee on Physical
Education and Medical Aspects of Sports issued a recommended procedure to the Kentucky High School Athletic Association for immediate implementation in 2002. This
procedure called for the determination of the Heat Index (using on site devices to measure Temperature and Relative Humidity), and a guideline for activity to be conducted at that time based on the Heat Index reading. Though other procedures and measurements were considered, the application of the Heat Index appeared to be most readily implementable on a state wide basis, and appeared to be reliably tested in other areas.
Through the first five years of use of the procedure, minor adjustments were made in the reporting requirements, and the on site devices to be used. In May, 2005, the Board of Control through its policies directed that all member school comply with the testing and reporting requirements. In October, 2006, the member schools of the Association overwhelming approved at their Annual Meeting, a proposal to make such reporting not simply a Board of Control policy, but a school supported and approved Bylaw as it approved Proposal 9 to amend KHSAA Bylaw 17
In March, 2007, the Kentucky Medical Association Committee on Physical Education and Medical Aspects of Sports recommended the elimination of all devices with the exception of the Digital Sling Psychrometer as a means of measuring at the competition/practice site.
The procedure calls for the determination of the Temperature and Relative Humidity at the practice / contest site using a Digital Sling psychrometer It is important to note that media-related temperature readings (such as the Weather Channel, local radio, etc.), or even other readings in the general proximity are not permitted as they may not yield defensible results when considering the recommended scale. The readings must be made at the site.
Neither the KHSAA nor KMA has endorsed any particular brand of psychrometer and receives no endorsement fee or other consideration for any device sold. There are several models on the market that will properly perform the functions, including companies such as Medco and others.
The KHSAA or your local Certified Athletic Trainer haseasy access to catalogs with this type of equipment. In addition, the KHSAA web site has a variety of links to various dealers.
INDOOR AND OUTDOOR VENUES
While much of the original discussion concerning this package centered on outdoor sports, the Kentucky Medical Association Committee on Physical Education and Medical Aspects of Sports has advised the KHSAA that indoor sports, particularly in times of year or facilities where air conditioning may not be available, should be included in the testing. Such has been approved by the Board of Control as policy requirement. The recommendations contained in this package clearly cover both indoor and outdoor activity, as well as contact and non-contact sports.
PROCEDURE FOR TESTING
Thirty (30) minutes prior to the start of activity, temperature and humidity readings should be taken at the practice / competition site.
The information should be recorded on KHSAA Form GE20 and these records shall be available for inspection upon request. All schools will be required to submit this form. For 2007, there will be online reporting for submitting this form.
The temperature and humidity should be factored into the Heat Index Calculation and Chart and a determination made as to the Heat Index. If schools are utilizing a digital sling psychrometer that calculates the Heat Index, that number may be used to apply to the regulation table.
If a reading is determined whereby activity is to be decreased (above 95 degrees Heat Index), then re-readings would be required every thirty (30) minutes to determine if further activity should be eliminated or preventative steps taken, or if an increased level of activity can resume.”
HEAT STROKE IN SPORTS: CAUSES, PREVENTION, AND TREATMENT
E. Randy Eichner, M.D.
Professor of Medicine
Team Internist, Oklahoma Sooners
Department of Medicine
University of Oklahoma Health Sciences Center
Oklahoma City, Oklahoma
Reprinted from Gatorade Sports Science Institute “Sports Science Exchange” Volume 15 Number 3
Heat stroke is always a risk in summer sports, especially football and running.
Heat stroke is typically caused by a combination of hot environment, strenuous exercise, clothing that limits evaporation of sweat, inadequate adaptation to the heat, too much body fat, and/or lack of fitness.
Early recognition and fast treatment of evolving heat stroke can save lives.
Preventing heat stroke hinges on acclimation, hydration, pacing, cooling, and vigilance.
Heat stroke is a medical emergency. The life-saving adage is: cool first and transport second.
Summer football brings grueling workouts in brutal heat. For football players in the dog days, mild heat illness is common and grave heat stroke always a threat (Knochel, 1975). Since 1995, on average three players a year have died of heat stroke. Heat stroke also threatens runners and other athletes; in the 2001 Chicago Marathon, a young man in his first marathon collapsed of heat stroke at 26 miles and died soon after.
Heat illness can advance quickly in football players and runners, and early warning signs of heat stroke can be subtle. Yet early diagnosis and proper therapy can save lives; exertional heat stroke should be preventable. This article covers causes of heat stroke in sports and presents tips to recognition, prevention, and treatment.
Causes of Heat Stroke
Overmotivated athletes can overheat by doing too much too fast or trying to endure too long. An Australian runner, out of shape, sped to the front of a hot race and kept going hard until he dropped from heat stroke at 4.5 miles (Lee et al., 1990). The same happened to a novice runner who, on a mild day, sped up at the end of a six-mile race (Hanson et al., 1979). Both runners were lucky to live; speed and metabolic rate influence rectal temperature in distance racing (Noakes et al., 1991).
Agonizing tableaus of endurance were seen at the 1984 Los Angeles Olympic Games and the 1995 Hawaii Ironman Triathlon. In Los Angeles, marathoner Gabriela Andersen- Scheiss, not trained for heat, entered the stadium dazed and wobbling. In a final lap that seemed to last forever, she waved off help and collapsed at the finish. In Hawaii, seven-time winner Paula Newby-Fraser, losing her lead, skipped aid stations late in the run and collapsed near the end. After rest, cooling, and hydration, she was able to walk to the finish (Eichner, 1998).
Similar lessons come from the military. A soldier died of heat stroke marching at night, carrying extra weight. He completed just 2.5 miles (Assia et al., 1985). Running generates about twice the heat of marching. Of 82 heat-stroke cases in Israeli soldiers, 40% were from brief exercise, as in the first three miles of a run. Overmotivation was a risk factor (Epstein et al., 1999).
Football breeds a warrior mentality. Victims of heat stroke are described as “the hardest worker” or “determined to prove himself.” During a hard practice on a hot day, the never-quit mentality can work against a player.
The 1-2 Punch.
Most heat-stroke deaths in football occur on Day 1 or 2 of two-a-days. A similar 1-2 punch applies in the military. In studying 1,454 cases of heat illness in Marine-recruit training, researchers implicated heat stress on the prior day as a factor (Kark et al., 1996). So a prime time for heat stroke is the day after an exhausting and dehydrating day in the heat.
Heat and Humidity.
In summer sports, it?s not the heat, but the heat and humidity. In football, body temperature rises ? in a sawtooth line ? ever higher the longer practice goes on. So during a hard practice in full gear, heat stroke is possible at any combination of ambient temperature above 80 °F (26.7 °C) and relative humidity above 40% (Kulka & Kenney, 2002).
Getting heat-fit takes time. Lack of acclimation is a cardinal predictor of heat stroke in football. Triathletes unacclimated to the tropical heat of Hawaii also suffer. Acclimation, much of which occurs in a week or two, leads to better drinking and the body holds onto water and salt, increasing blood volume so the heart pumps more blood at a lower heart rate. Heat-fit athletes also sweat sooner, in greater volume, and over a wider body area, so they stay cooler.
Athletes in the heat can sweat 1-2 L an hour, and most athletes drink less than they sweat. The result is dehydration. Dehydrating only 2% body weight ? just five pounds in a 250-pound linebacker ? can impair physical performance (Walsh et al., 1994). Dehydration increases heart rate and decreases cardiac output. Perceived exertion of the work increases as dehydration drains mental sharpness and willpower along with muscle power and endurance. Dehydrated players also heat up faster (Latzka & Montain, 1999).
The football uniform insulates players. As more gear is added ? from shorts and shirt to pads and helmet to full uniform ? players heat up faster, get hotter, and cool slower (Kulka & Kenney, 2002). Runners too should avoid vapor-impermeable clothing that limits sweat evaporation. In 1999, actor Martin Lawrence jogged in heavy clothes and a wool hat in 100 °F (37.8 °C) to lose weight. He collapsed with a temperature of 107 °F (41.7 °C) and spent three days in a coma.
Heat Stroke and Body Mass.
Fat athletes are prone to heat stroke. Extra fat is an extra load, increasing exertional heat production. The NFL has nearly 300 players who weigh 300 pounds or more, six times as many as a decade ago. Nor is extra fat the only bulk problem. When a 270-pound player adds 30 pounds of muscle, he can generate more heat, but he does not add enough extra surface area to shed that extra heat. So huge lineman can be heat bombs.
Physical fitness, especially aerobic fitness, confers some of the same physiologic benefits as heat acclimation (Latzka & Montain, 1999). Fitness also makes workouts less taxing. So football players who come to camp fit are at lower risk of heat stroke.
In contrast, lack of fitness increases risk of heat illness. In a study of 391 cases of heat illness in Marine recruits, time to run 1.5 miles (and body mass index) predicted risk. A recruit unable to run 1.5 miles in 12 minutes (and with a body mass index over 22) had eight times the risk of heat illness in basic training as did one with a lower body mass and faster run time (Gardner et al., 1996).
Stimulants speed heat buildup, so products that speed players up heat them up. Amphetamine and cocaine are the most dangerous, but ephedra is the most prevalent. Many dietary supplements tout ephedra for weight loss or quick energy. But ephedra poses many health risks, including heat stroke. Heat-stroke risk is compounded by drugs that impair sweating, like some antihistamines, antispasmodics, and medications for depression.
Recognizing Heat Stroke
Heat stroke in football sometimes seems to hit with surprising speed. When this happens, a common theme of bewildered staff is, “But he got lots of fluids.” The misconception is that hydration prevents heat stroke. The truth is that hydrating is critical but not sufficient to prevent heat stroke. Stress fluids but think “beyond fluids.” All the factors described above can work together to cause heat stroke.
Compared to the other common causes of collapse in football ? trauma, heart disease, asthma, sudden blood clots tied to sickle cell trait (sickling crisis) ? heat stroke is often slow to evolve, and the vigilant observer can detect early warning signs and avoid the worst outcome. Heat stroke is always a threat during hard drills on hot days, especially in hefty players in full gear.
Early warning signs of impending heat stroke may include irritability, confusion, apathy, belligerence, emotional instability, or irrational behavior. The coach may be the first to note that a player, heating up, can no longer think clearly. Giddiness, undue fatigue, and vomiting can also be early signs. Paradoxical chills and goose bumps signal shutdown of skin circulation, portending a faster rise in temperature. The player may hyperventilate ? just as a dog pants ? to shed heat; this can cause tingling fingers as a prelude to collapse. Incoordination and staggering ? “running like a puppet on a string”? are late signs, followed by collapse with seizure and/or coma. Upon collapse, as in all three football players who died in 2001, core body temperature can be 108 °F (42.2 °C) or higher.
Preventing Heat Stroke
Cooler is Better.
The cooler athletes stay, the better they play. In team sports, take frequent cooling breaks. Provide shade, ice water, and misting fans for rest breaks. As the temperature rises, reduce practice pace and duration and increase rest breaks. Have players sit in cold tubs after practice. Hold practices earlier and later, with more time between ? time for rest, recovery, and cooling.
In hot road races, tips include: stay hydrated; run comfortably, avoid long sprints; “read” your body; and seek help early for illness. Confusion can limit self-diagnosis, so race monitors can help. Runners in trouble can become belligerent, refusing to stop until they collapse. Naïve crowds may urge on suffering athletes, chanting, “Keep going, you can make it.” Monitors can recognize early warning: incoherence, irrational or bizarre behavior, or poor competitive posture (Eichner, 1998).
Hydration helps prevent heat stroke, but there is no advantage to consuming fluid in excess of sweat loss. Likewise it?s not necessary to overhydrate the night before or during the hours prior to a long run or practice. Teach athletes to drink for their needs. During training have them weigh in before and after a workout and learn to adjust fluid intake to minimize weight loss. If weight loss does occur, rehydration after activity is critical; drink 20-24 ounces of fluid for every pound of weight loss. Also, eat foods with a high water content (fruits & vegetables). A sports drink beats plain water because it has sugars to fuel muscles and brain, flavoring to encourage drinking, and sodium to hold fluid in the body and help replace sweat losses.
High heat can overwhelm even physically fit and hydrated players. A week or two of moderate physical activity in the heat, say jogging 30-45 minutes a day, can jump-start heat acclimation. Athletes should never go from a sedentary, airconditioned life into a hard-charging summer athletic camp.
Bird-dog the Big Guys.
In football, focus on high-risk players. Spot subtle signs of physical or cognitive decline. Weight loss the first few days is fluid loss, not fat loss. Dizziness and drop in blood pressure on standing signal fluid and sodium depletion. Urine should resemble lemonade, not apple juice. Weigh before and after practice. Morning weight should be back up, near baseline, and body temperature should be normal before the player takes the field. When in doubt, hold them out.
In football, limit gear in the heat. Suit-up in stages in summer camp: shorts and T-shirt the first day or two; then add helmet; then shoulder pads and jersey; finally the full uniform. Remove helmet and pads for fitness runs. Boxers and wrestlers should not run in plastic suits to lose weight.
Counter the Culture.
Some football players are overmotivated by pride and driven by tough coaches. They believe no limits exist. They ignore warning signs. Never let the warrior call the shots. Some runners also have a never-say-die mentality. The man who died of heat stroke in the Chicago Marathon may have pushed the pace trying to keep up with his brother. Heat stroke is rare in female athletes. And in Marines, although attack rates are the same by gender, heat illness is milder in females (Kark et al., 1996). These gender trends raise questions of biology and behavior.
Train, Don’t Strain.
Start slow. Athletes cannot safely start full tilt in stifling heat. Other than massive bleeding, exercising all-out in extreme heat is the greatest strain on the cardiovascular system. Pace and duration should “start low and build slow.” Don?t drive halfway to heaven on the first day.
Off-field behavior also counts. Athletes sleeping poorly or ill, especially with vomiting, diarrhea, or fever, are more prone to heat stroke. The same applies to taking diuretics or drinking alcohol. Monitor all medications.
Linemen and other athletes at risk of heat stroke may benefit from pre-cooling before workouts. A half hour in a cold bath will reduce core temperature and increase the buffer against heat stroke. Pre-cooling mimics Mother Nature in that after a week of daily exercise in the heat, basal body temperature is reduced about 0.9 °F (0.5 °C) (Buono et al., 1998). Another benefit may be improved hot-weather running or cycling (Booth et al., 1997; Gonzalez-Alonzo et al., 1999). Using cold towels or splashing cold water on face, head, and neck provides a psychological boost but little physiological benefit.
Treating Heat Stroke
In heat stroke, every minute counts. When core temperature is very high, body and brain cells begin to die, so fast cooling is vital. Early features are subtle central nervous system (CNS) changes ? altered cognition or behavior ? and core temperature over 104-105 °F (40.0-40.6 °C). When an athlete collapses, the best gauge of core temperature is rectal temperature; oral, axillary, or ear-canal temperature will not do. Advanced features are collapse with wet skin, core temperature over 106-107 °F (41.1- 41.7 °C) and striking CNS changes ? delirium, stupor, seizures, or coma (Roberts, 1998).
Field treatment is fast cooling. No faster way to cool exists than dumping the athlete into an ice-water tub. Submerge the trunk ? shoulders to hip joints. Research suggests ice-water immersion cools runners twice as fast as air exposure while wrapped in wet towels (Armstrong et al., 1996). The Marines also use ice-water cooling (Kark et al., 1996). Recent field research with volunteer runners suggests cold water may cool as fast as ice water (Clements et al., 2002).
(Walmart Kiddy Pool with Large Ice Cooler and hose located beside. Dump Ice, Water and Athlete in Kiddy Ice Pool instantly. mbmsrmd)
Check the athlete every few minutes for rectal temperature, CNS status, and vital signs. Useful is an indwelling rectal probe with a thermometer. To prevent overcooling, remove the athlete from the tub when rectal temperature drops to 102 °F (38.9 °C). An athlete can be cooled from 108-110 °F (42.2-43.3 °C) to 102 °F (38.9 °C) in 15-30 minutes (Roberts, 1998).
Cool first, transport second. Send the heat-stroke athlete to the hospital after cooling. With fast cooling, survival rate approaches 100% (Kark et al., 1996). In fact, fast cooling can allow athletes to walk away in good health. For example, yearly at the Falmouth Road Race, up to 10-15 runners collapse with temperatures from 106-110 °F (41.1-43.3 °C), but over a decade nearly all such runners, after ice-water immersion, walked away. After cooling, runners are observed for 20-60 minutes to ensure they are drinking fluids and have normal vital signs and good cognition (Roberts, 1998).
We need more data on recovery. Anecdotally, most runners cooled on-site return to racing in weeks. Some research suggests heat-stroke patients may have brief or lasting heat intolerance, but whether this is innate or a result of the heat stroke is unclear (Shapiro et al., 1979). Other research suggests 90% of heat-stroke patients have normal heat tolerance within two months (Armstrong et al., 1990). Long-term follow-up of 922 cases of heat illness in Marine recruits is encouraging ? subsequent serious heat illness occurs in less than 1% of these Marines per year (Phinney et al., 2001). It seems likely that most athletes treated early for heat stroke and educated on preventing it can return safely to their sport within weeks.
Many factors ? environmental and personal ? contribute to heat stroke. Early warning signs of impending heat stroke may include irritability, confusion, apathy, belligerence, emotional instability, irrational behavior, giddiness, undue fatigue, chills, goose bumps, and vomiting. Practical tips for preventing and treating heat stroke in sports are outlined, with the vital adage being: Cool first; transport second. Research on recovery is sparse, but it seems likely that most athletes treated early for heat stroke can soon safely return to their sport.
Assia, A., Y. Epstein, and Y. Shapiro (1985). Fatal heatstroke after a short march at night: a case report. Aviat. Space Environ. Med. 56:441-442.
Armstrong, L.E., J.P. De Luca, and R.W. Hubbard (1990). Time course of recovery and heat acclimation ability of prior exertional heatstroke patients. Med. Sci. Sports Exerc.22:36-48.
Armstrong, L.E., A.E. Crago, R. Adams, W.O. Roberts, and C.M. Maresh (1996). Whole-body cooling of hyperthermic runners: Comparison of two field therapies. Am. J. Emerg. Med. 14:355-358.
Booth, J., F. Marino, and J.J. Ward (1997). Improved running performance in hot humid conditions following whole body precooling. Med. Sci. Sports Exerc.7:943-949.
Buono, M.J., J.H. Heaney, and K.M. Canine (1998). Acclimation to humid heat lowers resting core temperature. Am. J. Physiol. 274:R1295-R1299.
Clements, J.M., D.J. Casa, J.C. Knight, J.M. McClung, A.S. Blake, P.M. Meenen, A.M. Gilmer, and K.A. Caldwell (2002). Ice-water and cold-water immersion provide similar cooling rates in runners with exercise-induced hyperthermia. J. Athl. Train. 37:146-150.
Eichner, E.R. (1998). Treatment of suspected heat illness. Int. J. Sports Med. 19:S150-S153.
Epstein, Y., D.S. Moran, Y. Shapiro, E. Sohar, and J. Shemer (1999). Exertional heat stroke: a case series. Med. Sci. Sports Exerc.31:224-228.
Gardner J.W., J.A. Kark, K. Karnei, J.S. Sanborn, E. Gastaldo, P. Burr, and C.B. Wenger (1996). Risk factors predicting exertional heat illness in male Marine Corps recruits. Med. Sci. Sports Exerc.28:939-944.
Gonzalez-Alonzo, J., C. Teller, S.L. Andersen, F.B. Jensen, T. Hyldig, and B. Nielsen (1999). Influence of body temperature on the development of fatigue during prolonged exercise in the heat. J. Appl. Physiol. 86:1032-1039.
Hanson, P.G. and S.W. Zimmerman (1979). Exertional heatstroke in novice runners. JAMA 242:154-157.
Kark, J.A., P. Q. Burr, C.B. Wenger, E. Gastaldo, and J.W. Gardner (1996). Exertional heat illness in Marine Corps recruit training. Aviat. Space Environ. Med. 67:354-360.
Knochel, J.P. (1975). Dog days and siriasis. How to kill a football player. JAMA 233:513-515.
Kulka, T.J. and W.L. Kenney (2002). Heat balance limits in football uniforms. How different uniform ensembles alter the equation. Phys. Sportsmed. 30(7):29-39.
Latzka, W.A. and S.J. Montain (1999). Water and electrolyte requirements for exercise. Clin. Sports Med. 18:513-524.
Lee, R.P., G.F. Bishop, and C.M. Ashton (1990). Severe heat stroke in an experienced athlete. Med. J. Austr. 153:100-104.
Noakes, T.D., K.H. Myburgh, J. Du Plessis, L. Lang, M. Lambert, C. Van Der Riet, and R. Schall (1991). Metabolic rate, not percent dehydration, predicts rectal temperature in marathon runners. Med. Sci. Sports Exerc.23:443-449.
Phinney, L.T., J.W. Gardner, J.A. Kark, and C.B. Wenger (2001). Long-term follow-up after exertional heat illness during recruit training. Med Sci. Sports Exerc. 33:1443-1448.
Roberts, W.O. (1998). Tub cooling for exertional heatstroke. Phys. Sportsmed. 26(5):111-112.
Shapiro, Y., A. Magazanik, R. Udassin, G. Ben-Baruch, E. Shvartz, and Y. Shoenfeld (1979). Heat intolerance in former heatstroke patients. Ann. Intern. Med. 90:913-916.
Walsh, R.M., T.D. Noakes, J.A. Hawley, and S.C. Dennis (1994). Impaired high-intensity cycling performance time at low levels of dehydration. Int. J. Sports Med. 15:392-398.
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2011 PRESEASON FOOTBALL HEAT STROKE DEATHS
Aug. 8, 2011 New guidelines from American Acadamey of Pediatrics: Sports in Heat OK With Precautions by Lindsey Tanner, AP Medical Writer. That is aDangerous, Reckless Statement by Ivory Tower, White Gowned Doctors not on the Front Line of High School Football with all the information.
“WELL GUESS WHAT, GURDON HIGHT SCHOOL COACH TOOK PRECAUTIONS. THEY WERE PRACTICING AT 8:30pm “
Heat Stroke # 5 this 2011 Preseason- Aug 10, 2011 LITTLE ROCK – Gurdon High School football player died Tues night collapsed ~ 8:30 p.m during a practice. Wed. 15 yo Montel Williams, soph this season, in full-pads practice for over an hour http://www.arkansasonline.com/news/2011/aug/10/gurdon-high-school-football-player-collapses-dies/
4 High School Football Athletes died in the last ~8 days in the South.furing football practice, 1SC, 2GA, 1FL. Probably all heat related. Awaiting Autopsy Reports. sent in email Monday, August 08, 2011 6:31 AM
Lexington, KY – A Lexington company has begun marketing a body patch that can warn active, outdoor people if their body temperature rises to a dangerous level. The single-use, disposable IONX Body Alert Temperature Patch, created by IONX International, is nicknamed the Hot Dot.
When worn on strategic body parts, the Hot Dot will change color, from black to bright yellow, when the body’s temperature reaches a level that could cause heat stroke or heat exhaustion. After the wearer takes note of the warning and responds by drinking liquids or cooling down, the patch returns to its original black color, signaling that the body’s temperature is within normal range.
The cloth patch has a thermo-chromatic (heat-sensitive) chemical layer in it that changes color based on a temperature setting established in its chemical makeup.
Prepared by Stephen T. Hougen, M.D., F.A.C.S., GETAC Injury Prevention Committee, August 19, 2009 (GETAC – Governor’s EMS & Trauma Advisory Council, Texas Department of State Health Services)
There are no new lessons to be learned about heat stroke, only new athletes, coaches, trainers, and parents to educate. There are no new events, just the same well-known circumstances that are repeated every year with new, unwary victims. At least 21 young athletes have died from heat stroke during the last several years. (30, 31)
The deaths of Korey Stringer, the Minnesota Viking’s Pro Bowl offensive lineman, on August 1, 2001 and Eraste Autin, the University of Florida’s freshman who collapsed July 19, 2001 after a summer training session and spent six days in a coma before dying, are only two of many widely publicized examples of tragic, but preventable, deaths. We may also recall Matthew Thomas, the 14 year old Victoria Texas High School freshman, who succumbed shortly after football practice during a 92-degree afternoon on August 12, 2003, 17 year old Chris Stewart from Oklahoma City who died of heat stroke in August 2005, (21-28) and Max Gilpin, a 15 year-old Louisville, Kentucky player who collapsed and died when his temperature rose to 107 degrees following a series of wind sprints called “gassers” on a 94 degree day in August 2008. (48, 49, 50, 51, 52, 53)
The typical heat stroke victim is usually not well-acclimatized to the Texas heat. It should be no surprise that student athletes who have spent the summer watching TV and playing video games in the comfort of their air-conditioned homes may not be physically prepared for exertion in the heat. (6, 17)
Overall, however, student athletes are extremely motivated, perhaps sometimes even overzealous, individuals who may push themselves beyond their level of endurance and heat tolerance in their attempt to excel in their sport. (17,19,32,43) During team try-outs an athlete may feel pressured to perform beyond his capability in the heat, ignoring signs and symptoms of impending heat-related illness.
When the brain signals that something was wrong, the athlete can override his brain and keep exerting himself. A competitive athlete is not going to voluntarily take himself out of the competition, an action which might jeopardize his place on the team. Disregarding his brain’s signals, the athlete consciously continues to participate beyond the threshold of safety. His brain even starts to fail, manifested by confusion and atypical behavior, as he generates more body heat than he can possibly lose. His body simply overheats.
The human body has a thermal regulation system that strives to maintain temperature at 98.6 degrees Fahrenheit. That temperature is the comfort zone in which all human biological systems operate efficiently. (46) The body dissipates heat with radiation, conduction, convection, and from the evaporation of sweat. (2, 43, 46) Radiation transfers heat energy via infra-red waves from a hotter to a cooler source, like the glow from a red-hot branding iron as skin capillaries dilate to increase blood flow causing the skin to become red and hot. Heat transfer through conduction occurs through direct contact with an object such as heat gain by touching a hot surface or heat loss by direct contact with ice packs or cold water immersion.
Convection occurs when a cool breeze flows over the hot surface causing heat loss into the ambient air much like heat leaving the cooling plates of a car radiator. Finally, the evaporation of sweat also causes heat loss as liquid water turns into water vapor. The cooling effect of sweating islessened by high humidity that prevents evaporation. Sweating is also decreased by dehydration from insufficient water intake, normal respiratory water loss, and fluid losses from vomiting. When fluid losses are great, the body starts to lose intravascular volume—the volume of fluid in arteries and veins. (45)
The pulse rate increases as the heart tries to maintain circulation and an adequate blood pressure. To avoid going into shock, the body closes capillaries to direct blood flow away from the skin, gut, and muscles to more vital organs, such as the brain, kidneys, and liver. (44) When the skin capillaries close, the blood leaves the skin surface. Sweating may stop. The skin becomes cool and clammy and goose bumps may appear. (17, 18, 46) The shunting of blood from the skin is what causes people to feel chilled when going into shock. Vomiting and muscle cramps may occur. (7, 38) The failure of the body’s cooling mechanisms—the radiator effect and the sweating-evaporation process—causes an internal heat surge.
Excessive accumulation of heat energy causes thermal injury to biological systems including breakdown of muscle tissue, rhabdomyolysis, potentially irreversible multi-organ failure, and sometimes death. (2, 8, 9, 12, 16, 17, 32, 43, 46)
Early symptoms of heat injury include: thirst, dizziness, lightheadedness, paleness, headache, poor concentration, missed assignments, irritability, altercations, apathy, weakness, fatigue, and a feeling of being limp. More advanced symptoms include: warm and flushed (red) skin, muscle cramping, nausea, and vomiting.
Emergency symptoms of impending heat stroke include: the appearance of cool and clammy skin, absence of sweating, dry skin, rapid breathing, confusion, a change in personality often perceived as “goofing off” and not following instructions, fainting, and eventual collapse. (2,3,11,12,13,14,17,20,31,43)
Treatment must include immediate rapid cooling in the field with ice packs and cold water, with total body immersion if possible.
Restrictive clothing should be removed. Every minute of exposure at high core temperatures causes more tissue damage. Every minute counts in a “heat” attack, much like a heart attack. (31)
Emergency hospital care is needed for anyone who collapses during heat-related exertion, and rapid cooling should begin in the field and continued during transport to the hospital. (1,12,17,31,32,33,43)
Prevention strategies are the main approach to reducing the risk of exertional heat stroke. The following measures are recommended.
1. Gradually acclimatize participants to heat with light work-outs the first week of practice. Most heat strokes occur during the initial few days of practice when athletes are not acclimatized to the exercise intensity and equipment. (9,17,18,31,32,43,46)
2. Provide free, unlimited, unquestioned access to cool, palatable water. (5,19,30,31,43)
3. If a player is thirsty he is already dehydrated. He must be allowed to drink without having to ask permission. Drinking 8 ounces of a balanced electrolyte solution such as found in sports drinks every 15 minutes, up to a liter per hour, is recommended before a player feels thirsty. A single swallow from a squirt bottle is not sufficient fluid replacement. (9,11,12,13,16,31,43)
4. Weigh players before and after practice to verify proper fluid replacement. If players lose weight during practice, they are dehydrated and at risk of compromising one of their chief means of cooling — sweating. (17,20,43,46)
5. Take mandatory breaks in the shade and allow players to remove helmets. (31,43)
6. Bathroom facilities should be available, as their absence may discourage adequate oral hydration by players who may feel embarrassed if they need to urinate.
7. Although water and balanced electrolyte solutions are helpful, salt tablets are not recommended. (10,11,12,13,14,29) Like drinking seawater, taking salt pills can be harmful. In order to eliminate excess salt the body loses water, water it can not afford to lose during conditions of over-heating. (46,47)
8. Good hydration alone does not prevent heat stroke! Even if one drinks plenty of water and sports drinks and is making lots of dilute urine (a sign of good hydration), heat stroke can still occur if the body generates or absorbs more heat that it can dissipate by its usual cooling mechanisms. (16,17,19,43,46)
9. Exposure to direct sunlight increases the radiant energy absorbed as heat. Test this phenomenon by placing a hand on the hood of a car parked in direct sunlight compared with a car parked in the shade. The air temperature is the same, but the vehicle in the sun is much hotter than the one in the shade. If a practice is held in direct sunlight, the heat index increases by up to 15 degrees F, and those 15 degrees should be added to the heat index given by the National Weather Service to determine the risk of heat-related injury. (2,37)
10. Do not allow any outdoor activity if the heat index is 95 or greater. [mbmsrmd]
11. The above guidelines may vary with the age, weight, and conditioning of individual players. To be on the safe side, in his newspaper column “To Your Good Health” Dr. Paul Donohue recommends suspension of practice if the heat index is 90 or greater (Exertional Heat Stroke, a Preventable Cause of Death, Victoria Advocate, July 14, 2007, page E-5). (35)
12. Monitor players for symptoms of heat exhaustion. (1) A player is unlikely to admit that he is feeling weak or lightheaded. He is unlikely to pull himself out of the practice. A buddy system, like one used by scuba divers, may help one player protect and monitor another. (17,18,31,32,37)
13. If a player is dizzy, lightheaded, not “feeling right” or vomits, he must stop practice immediately and be allowed to cool off in the shade with ice packs and soaked towels, or with a cool water mist and fan, with his uniform removed. Vomiting should prohibit anymore practice that day. Notify the parents so the player is monitored at home and properly fed and rehydrated. (12,13,14,17,31)
14. If a player collapses, or if exertional heat stroke is suspected, a player should be rapidly cooled by immediately removing all equipment and uniforms and immersing him cooled in a tub of ice water until EMS can assume care and transport to the hospital. It is important to cool first, transfer second. Every minute spent above a body core temperature of 104 degrees F, measured rectally or with an esophageal probe, worsens the tissue damage and increases the risk of death.(2, 12, 13, 14, 17, 19, 20,31,32,43,46) Oral, tympanic membrane, and temporal artery temperatures do not accurately measure core temperatures in this setting. (17,43)
15. Avoid stimulants such as highly caffeinated “energy-boosting” drinks (which have fluid-losing diuretic effects), ephedra, ephedrine, amphetamines, and cocaine, which can cause cardiac rhythm disturbances. (2,12,17,32)
16. Practice during the cooler parts of the day, when the heat index is lowest, preferably less than 90, although practice with a heat index of less than 105 may be more practical and acceptable, with appropriate precautions. (17,43)
17. Do not gauge the intensity of practice by pushing players until they get cramps, vomit, or collapse. Remember that if a player is having one symptom, more are likely to follow, possibly in a rapid cascade of downhill events. (32,46)
18. Heat stroke has occurred in marathon runners in relatively cool temperatures of 60 degrees! (32,33,43) The fundamental principle causing exertional heat injury is the generation of heat faster than the heat can be lost. The result is a harmful rise in body core temperature. A core (rectal) temperature of 104 is very dangerous; at 108 the person is likely to die. (1,2,12,16,17,31,38,43,46)
19. The sickle-cell trait, present in 8% of the black population and also found in people of Mediterranean descent, can pre-dispose an athlete to a sickle-cell crisis during times of heat-related stress. A high index of suspicion is necessary when such participants demonstrate any sign or symptom of illness, such as muscle cramps or abdominal pain. Treatment with immediate intravenous hydration and supplemental oxygen may be life-saving and may prevent damage to vital organs. (1,15,17,40,41,42,43)
20. Players who are ill with fever, diarrhea, vomiting, or viral illnesses should refrain from exertion in the heat. (17,19,32,43)
21. Create a team effort to prevent dehydration and heat stroke involving the coaches, trainers, administrators, parents, and athletes. (31)
22. Remember that poor concentration, missed assignments, frequent penalties, irritability, altercations on the field, muscle cramps, loss of liveliness and spirit, apathy, and increasing frustration of the players and coaches in the fourth quarter may be prevented by what is done in the first quarter regarding proper fluid and electrolyte replacement. A player’s poor performance may not be due to lack of desire or not wanting “it” enough. Sub-par performance may simply be due to a lack of water and over-heating! (16,19,31,43) Like continuing to drive a car with a dry radiator, engine failure is likely to occur.
23. Consider posting an educational heat stroke poster in the locker room. (39)
24. Refer to the accompanying temperature/humidity chart to determine the heat index, or use the programs on www.zunis.org to determine the wet bulb globe temperature and follow the football guidelines and recommended precautions. (37)
For example, the National Weather Service uses the Steadman Heat Index on the following page to provide hot weather advisories to the general public. Using the table, an air temperature of 90 with a relative humidity of 60% produces a Heat Index of 100. This heat index is associated with a low risk of heat-related illness, but appropriate precautions should be taken because heat injury can still occur. If players are exposed to direct sunlight, however, the heat index in the same conditions rises to 115 degree F, a danger zone for exertional heat injury. (37)
During practice the coach should ask this question: “Are my players being exposed to direct sunlight casting shadows shorter than their height?” If the answer is “Yes” then add 15 degrees to the heat index chart and take appropriate precautions, such as practicing early in the morning, late in the evening, or inside a gym. (2,37,43)
A heat index of 105 and greater represents a danger zone, and heavy exertion should be avoided. In addition, mandatory breaks in the shade with helmets off and mandatory consumption of 8 ounces of water or a sports drink every 15 minutes should be the rule. A few swallows from a squirt bottle are not sufficient to maintain adequate hydration. Because the judgment of the athlete may be impaired in this setting, the player is unlikely to pull himself out of training exercises. Therefore, trainers and coaches should be observant, monitor their athletes for any symptoms of heat-related illness, and insist that players be removed and protected from dangerous environmental conditions. Prevention and treatment strategies must be in place. (4,5,17,19,43) Remember the advice of experts: “the cooler you stay, the better you play.” (17,18,19)
Note: Exposure to full sunshine can increase HI values by up to 15° F
Alternatively, add 5° F to the temperature when athletes are exposed to direct sunlight
Green Highlighted Heat Index: 90—104. When the heat index is between 90° F and 104° F, heat exhaustion and heat cramps are possible with prolonged exposure and physical activity. Ad lib access to cool water is necessary. Mandatory breaks in the shade every 20 to 30 minutes and extra fluids (water and/or sports drinks) are recommended. Ice water and cold, wet towels for rapid cooling in the shade should be immediately available. Cooling water mist fans are desirable. Observe players carefully!
Yellow Highlighted Heat Index: 105—129. Practice is dangerous in this setting. Under these conditions, instructional “walk-through” drills with minimal running and no contact should be considered. Ad lib access to cool water is necessary. Mandatory breaks in the shade every 15 to 20 minutes and extra fluids (water and/or sports drinks) are needed. An ice water tub for total body immersion or cold, wet towels for rapid cooling in the shade should be immediately available. Cooling mist fans are helpful.
Red Highlighted Heat Index: 130 and Higher. Outdoor exposure and any type of outdoor practice should be prohibited, as heat stroke risk is very great at this level of humidity and temperature. The body’s ability to cool by convection and evaporation of perspiration is severely impaired. In fact, in this environment the body will passively absorb heat from the ambient air and direct sunlight, and cooling by the sweating-evaporation mechanism is not possible because evaporation does not readily occur. Any exertion under these circumstances produces a high risk for exertional heat stroke.
Prepared by Stephen T. Hougen, M.D., F.A.C.S., GETAC Injury Prevention Committee, August 19,2009
Heat Stroke References
1. Vertuno Jim, The Associated Press, Longhorns Tackling the Heat: Pill Helping Texas Survive Rising Temperatures, published by the Victoria Advocate, August 15, 2007.
2. Hyperthermia, Wikipedia Encylopedia, October 2006, Retrieved from “http://en.wikipedia.org/wiki/Hyperthermia”
3. Heat Illness, Heat Exhaustion, Heat Stroke. The Nemours Foundation/Kids Health at www.revolutionhealth.com January 3, 2007.
4. Joseph Rampulla, MS,APRN,BC (June 2004). Hyperthermia & Heat Stroke: Heat-Related Conditions (pdf). The Health Care of Homeless Persons pp.199-204. Boston Health Care for the Homeless Program. Retrieved on 2007-02-22 at: http://www.bhchp.org/BHCHP%20manual/pdf_files/part2_PDF/Hyperthermia.pdf .
5. “Are you ready for extreme heat?” Courtesy: Federal Emergency Management Agency, Department of Homeland Security. Available from FEMA at: www.fema.gov/areyouready/heat.shtm. Updated August 20, 2007. This information may have changed or been updated since it was accessed. For the most current information, contact FEMA at http://www.fema.gov/.
6. Scott Anderson “Preventing Muscle Cramping in Football”. Coach and Athletic Director. May 2001. At www.FindArticles.com, 15 September 2007. http://findarticles.com/p/articles/mi_m0FIH/is_10_70/ai_n18611880 E.
7. Randy Eichner “Muscle cramps: the right ways for the dog days”. Coach and Athletic Director. August 2002. FindArticles.com. 15 Sep. 2007. http://findarticles.com/p/articles/mi_m0FIH/is_1_72/ai_n18613963.
8. Maddali Sirish, Rodeo Scott, Barnes Ronnie, Warren Russell, Murrell George: Post-exercise Increase in Nitric Oxide in Football Players with Muscle Cramps. The American Journal of Sports Medicine 26: 820-824, 1998.
9. Ruiz E J, Mitchell I D, Eberman L E, Cleary M A. Severe dehydration with cramping resulting in exertional rhabdomyolysis in a high school quarterback. In Cleary M A, Eberman LE, Odai ML eds. Proceedings of the Fifth Annual College of Education Research Conference: Section on Allied Health Professions. April 2006; 1: 31-35. Miami: Florida International Univeristy. http://coeweb.fiu.edu/research_conference/.
10. Cleveland Minot. Musle Cramp. University of Illinois Medical Center at Chicago: Health Library, at www.uimc.discoveryhospital.com, March 13, 2000; reviewed January 4, 2007. “Salt tablets are not useful and should be avoided.”
11. Texas Children’s Hospital. Preventing Heat Illness. Texas Children’s Hospital: Caring for Your Child’s Health at www.texaschildrenshospital.org, 2005. “Salt pills are unnecessary and possibly dangerous.”
12. Centers for Disease Control and Prevention. Frequently Asked Questions about Extreme Heat. Emergency Preparedness and Response Website at www.bt.cdc.gov/disasters/extremeheat/faq.asp. August 15, 2006. “Do not take salt tablets unless directed by your doctor.”
13. Gillis Rick (reviewer). Heat-Related Illness Can Quickly Become Serious. Healthlink: Medical College of Wisconsin at:
Prepared by Stephen T. Hougen, M.D., F.A.C.S., GETAC Injury Prevention Committee, August 19,
www.healthlink.mcw.edu/article/1031002770.html, June 28, 2007. “Salt pills should not be used without first asking your health care provider.”
14. Taylor-Oring Leslie. Is it Heat Exhaustion or Heat Stroke? Tae Park Tae Kwon Do at: www.eod.gvsu.edu/tkd/newpage22.htm. March 14, 1999. “Give them cool liquids—NO SALT PILLS.”
15. Eichner Randy. Curbing Muscle Cramps: More than Oranges and Bananas. Hot Topics in Sports Nutrition. Gatorade Sports Science Institute, at: www.gssiweb.com/ShowArticle.aspx?articled=619. July 25, 2003.
16. Coyle Edward. Fluid and Carbohydrate Replacement During Exercise: How Much and Why? Gatorade Sports Science Institute, Sports Science Exhange #50, Volume7 (1994), Number 3, at: www.gssiweb.com/Article_Detail.aspx/articleid=23&level=2&topic=2.
17. Eichner Randy. Heat Stroke in Sports: Causes, Prevention, and Treatment. Gatorade Sports Science Institute, Sports Science Exchange #86, Volume 15 (2002), Number 3, at: www.gssiweb.com/Article_Detail.aspx?articleid=597&level=2&topic=7.
18. Eichner Randy. Heat Stroke in Sports: How to Protect Yourself and Help Your Teammates. Gatorade Sports Science Institute, Sports Science Exchange #86, Volume 15 (2002), Number 3 Supplement, at: www.gssiweb.com/Article_Detail.aspx?articleid=597&level=2&topic=7.
19. Murray Robert, Eichner Randy. Preventing Heat Illness: Keeping Athletes from Falling into Danger Zones. Gatorade Sports Science Institute, Sports Science Library at: http://gssiweb.com/Article_Detail.aspx?articleid=570&level=2&topic=7.
20. Casa Douglas, Murray Robert. Sports Science News: Preventing Exertional Heat Illness: A Consensus Statement. Gatorade Sports Science Institute, Sports Science Library, 2007, at: http://gssiweb.com/Article_Detail.aspx?articleid=625&level=2&topic=7.
21. Conrad Mark. Mark’s View: Heat Stroke and Football Practice (A comment on the heat stroke death of Minnesota Viking Korey Stringer). Mark’s Sportslaw News, 2001, at: www.sportslawnews.com.
22. CNN News. Vikings football player dies of heat stroke, at: www.CNN.com./U.S., August 1, 2001. This is a CNN news story about Korey Stringer.
23. Associated Press, Mankato, Minnesota. Vikings tackle Stringer dies from heatstroke, August 2001.
24. The Associated Press, Gainesville, Florida: Florida player Autin dies six days after heat stroke. Volume 101, No. 187, Thursday, July 26, 2001. This article discusses the heat stroke death of 18 year old freshman Eraste Autin who collapsed during a work out in 88 degrees, 72% humidity, heat index of 100.
25. Smith Michael. Football Practice Heat Stroke Deaths Preventable (An article about the heat stroke death of 18 year old Chris Stewart). MedPage Today, Daily Headlines, Oklahoma City, August 18, 2005.
26. Sparks Tara. Death has parents concerned. Victoria Advocate, page 1, August 15, 2003 at: www.nl.newsbank.com/nl-search/we/Archives?p_product=VA&P_t.
Prepared by Stephen T. Hougen, M.D., F.A.C.S., GETAC Injury Prevention Committee, August 19,
This article describes a parents’ safety meeting following the death of 14 year-old Matthew Thomas.
27. Victoria Advocate staff writer. Autopsy not yet released. Victoria Advocate, page 1, August 15, 2003, at: www.nl.newsbank.com/nl-search/we/Archives?p_product=VA&P_t.
28. deLench Brook. To Nineteen Youth Athletes Dying Young. MomsTeam, A Parents Trusted Youth Sports Source, at www.momsteam.com. August 25, 2007.
29. Reddy Vinay. Heat Cramps, Heat Exhaustion, and Heat Stroke. Dr. Reddy’s Pediatric Office on the Web at http://www.drreddy.com, 1/12/07.
30. Williamson David. UNC Warns of Possible Heat Strokes for High School Atheletes, at www.unc.edu//depts/nccsi, 2004.
31. Roberts William. Death in the Heat: Can Football Heat Stroke be Prevented? Current Sports Medicine Reports. (3), 2004.
32. Roberts William. Common Threads in a Random Tapestry: Another Viewpoint on Exertional Heatstroke, The Physician and Sports Medicine. 33(10) 2-5, October 2005.
33. Roberts William. Exertional Heat Stroke during a Cool Weather Marathon: A Case Study. Medicine & Science in Sports & Exercise, Official Journal of the American College of Sports Medicine, pages 1197-1203, January 2006 at http://www.acsm-msse.org.
34. Fighting Heat Stress, at http://fighting_heat_stress,asp.htm.
35. Donohue Paul. Exertional Heat Stroke: A Preventable Cause of Death, To Your Good Health. Victoria Advocate, page E-5, Saturday, July 14, 2007.
36. Jung Alan, Bishop Phillip, Al-Nawwas Ali, Dale Barry. Influence of Hydration and Electolyte Supplementation on Incidence and Time to Onset of Exercise-Associated Muscle Cramps. Journal of Athletic Training 40(2): 71-75, April-June 2005.
37. The Zunis Foundation. How Hot is Hot? How Safe if Safe? At www.zunis.org, April 8, 2007.
38. It’s Hot, It’s Humid, It’s Sunny: Information on Heat and Sun-Related Illnesses. Street Medics, www.action-medical.net
39. Hirsch Larissa. Heat Exhaustion and Heat Stroke: A Poster. This is a handy instructional “Heat Sheet” found at www.kidshealth.com
40. Bergeron Michael F, Cannon Joseph G, Hall Elaina L, Kutlar Abdullah. Erythrocyte Sickling During Exercise and Thermal Stress. Clinical Journal of Sport Medicine. 14(6): 354-356, November 2004.
41. Gallais Daniel Le, Bile Alphonse, Mercier Jacques, Paschel Marc, Tonellot Jean Louis, Dauverchain Jean. Exercise-induced death in sickle cell trait: role of aging, training, and deconditioning. Medicine and Science in Sports and Exercise. 28(5): 541-544, May 1996.
42. Kark J A, Posey D M, Schumacher H R, Ruehle C J. Sickle-cell trait as a risk factor for sudden death in physical training. New England Journal of Medicine. (317): 781-787, September 1987.
43. Binkley Helen M, Beckett Joseph, Casa Douglas J, Kleiner Douglas M, Plummer Paul E. National Athletic Trainers’ Association Position Statement: Exertional
Prepared by Stephen T. Hougen, M.D., F.A.C.S., GETAC Injury Prevention Committee, August 19,
Heat Illnesses. Journal of Athletic Training. 37(3): 329-343, July-September 2002.
44. Guyton Arthur C, Hall John E. Circulatory Shock and Physiology of its Treatment, Chapter 24, Textbook of Medical Physiology, Eleventh Edition. W.B. Saunders Company, Philadelphia, June 2005.
45. Guyton Arthur C, Hall John E. The Body Fluid Compartments: Extracellular and Intracellular Fluids, Chapter 25, Textbook of Medical Physiology, Eleventh Edition. W.B. Saunders Company, Philadelphia, June 2005.
46. Guyton Arthur C, Hall John E. Body Temperature, Temperature Regulation, and Fever, Chapter 73, Textbook of Medical Physiology, Eleventh Edition. W.B. Saunders Company, Philadelphia, June 2005.
47. Guyton Arthur C, Hall John E. Regulation of Extracellular Fluid Osmolarity and Sodium Concentration, Chapter 28, Textbook of Medical Physiology, Eleventh Edition. W.B. Saunders Company, Philadelphia, June 2005.
48. Graves, Will. Case of Kentucky Coach puts Football on Trial. The Associated Press. The Victoria Advocate, page C-7, Friday, January 30, 2009.
49. Mahalo.com. Max Gilpin, at http://www.mahalo.com/max-gilpin
50. Louisville News, Homepage. Witness: Teen’s Death was Preventable. August 27, 2008. http://www.wlky.com/news/17315849/detail.html Copyright 2008 by WLKY.com.
51. Konz, Antoinette. 911 Call: PRP player drifted in, out of consiousness. Courier-Journal.com, Louisville, Kentucky at http://www.courier-journal.com/article/20081107/NEWS01/811070437/1008/rss01, November 7, 2008.
52. WLKY.com. PRP Football Player Collapses at Practice, In Critical Condition. http://www.wlky.com/sports/17267086/detail.html. August 22, 2008.
53. WLKY.com. PRP Football Player Dies 3 Days after Collapse in Practice. Louisville, Kentucky. At http://www.wlky.com/health/17280899/detail.html, August 27, 2009.
54. Binkley, Helen; Beckett, Joseph;Casa, Douglas; Kleiner, Douglas; Plummer, Paul. National Athletic Trainers’ Association Position Statement: Exertional Heat Illnesses. Journal of Athletic Training. 2002 Jul-Sep; 37(3): 329-343.
55. Parents’ and Coasches’ Guide to Dehydration and other Heat Illnesses in Children. National Safe Kids Campaign. Adapted from: Inter-Association task force on exertional heat illnesses consensus statement: National Athletic Trainers’ Association. June 2003. Available at: www.nata.org/industryresources/heatillnessconsensusstatement.pdf.
Prepared by Stephen T. Hougen, M.D., F.A.C.S., GETAC Injury Prevention Committee, August 19,