### Abstract
Heat illnesses are of major concern. More and more high school, college, and professional athletes are suffering from and/or dying from heat related illnesses. With all of the knowledge that medical professionals have in this day-in-age, there should be fewer instances of heat illnesses. Parents, coaches, and athletes also need to be aware of prevention and treatment procedures in case an emergency occurs. Heat stroke, the most serious heat illness, is a life threatening emergency and needs to be treated immediately. Ice water immersion is the best method for lowering the body temperature quickly and effectively.

**Key Words:** heat illness, heat stroke, heat index, prevention, treatment

### Introduction

After working on a sports medicine team for the last two years, exertional heat illnesses (EHI) were brought to my attention. I never knew how often they occurred or how life-threatening they could be. The purpose of this paper is to spread awareness to athletes, parents, and coaches, of the dangers of heat illnesses as well as how to prevent, treat, and return-to-play after an episode of heat illness. Heat illness-related deaths are on the rise, and I am curious to know why athletes are dying from heat injuries, such as heat stroke. In 2004, Coris et al. (4) stated, “the recent high-profile deaths of a collegiate athlete and a professional athlete in Florida and a professional athlete in Minnesota have the sports medicine and family medicine communities in a state of ‘high alert’ and searching for the most efficacious methods of preventing such tragedies.” In 2007, heat stroke was “the third leading cause of death in U.S. high school athletes.” (Coris, Walz, Konin, & Pescasio, 2007). Now, in 2010, “exertional heat stroke is the second leading cause of death among athletes, followed only by sudden cardiac death.” (Mazerolle, Scruggs, Casa, Burton, & McDermott, 2010). There are several different heat illnesses, ranging from mild to life threatening. Heat edema, heat rash, heat syncope, and heat cramps are the milder heat illnesses while heat exhaustion and heat stroke are more serious. Sunburns can also be considered a heat illness, ranging from mild to severe (1st degree to 3rd degree burns). Heat edema is swelling of the extremities, often found in people who are not used to activity, heat, or a combination of the two. Heat rash is a specific area of skin that has been irritated. It is often, red, inflamed, itchy, and tingly. Heat cramps are painful, involuntary muscle spasms, most often occurring in the abdomen or calf. Heat syncope is defined as an orthostatic dizziness which is a result of a sudden pooling of the blood in the extremities, commonly seen in marathon runners after they cross the finish line and abruptly stop running. Heat exhaustion occurs when an athlete has become dehydrated and has a core body temperature of approximately 102°F. This athlete will often feel dizzy, and present as pale, warm, and diaphoretic. They may also present with a rapid pulse and could be hyperventilating. Heat stroke is a life threatening emergency and care needs to be provided immediately. An athlete suffering from heat stroke will usually suddenly collapse. The athlete will have hot and dry skin, a rapid pulse, and a core body temperature above 104°F. Athletes, coaches, and medical staff will benefit the most from this paper as I provide information on how to prevent and treat heat illnesses, learn how to identify and modify risk factors, as well as considering communication and special circumstances. However, parents, family and friends of athletes can also benefit from this article in learning about ways to help if need be.

### Levels of Care

One of the best methods for preventing heat illnesses, if done correctly, is the preparticipation physical exam (PPE). The PPE is used to find any intrinsic risk factors that an athlete may have. It could be anything from low blood pressure, to heart problems, from asthma to obesity, and everything in between. “Several intrinsic risk factors that increase susceptibility to EHI have been identified, but information about their relative contributions is limited. These risk factors include (a) previous history of EHI, (b) poor cardiovascular (CV) fitness, (c) obesity, (d) inadequate heat acclimatization, (e) dehydration or electrolyte imbalance, (f) recent febrile illness, (g) sleep deprivation, (h) a ‘never give up’ or ‘warrior’ mentality (high level of motivation or zealousness), and (i) use of questionable drugs, herbs, or supplements.” (Eberman, & Cleary, 2009). Each of these risk factors needs to be considered so that appropriate actions can be taken to provide the safest situation possible for the athlete at risk. An athlete with any of the previously mentioned risk factors is at a higher risk for experiencing a heat illness.

Not only do members of the sports medicine team need to be educated, but athletes, coaches, and parents should also be informed about the risks, signs and symptoms, and treatments of heat illnesses. If an athlete is suffering from heat stroke, it is essential to provide immediate treatment, and with more people being educated properly, faster treatment may be more readily accessible. Hydration is one of the most important factors in preventing heat illness. It is important to educate athletes and coaches on proper hydration techniques. In some instances, mostly seen in football, coaches have withheld water breaks as a form of punishment or as a motivation technique. The coaches may or may not have known that withholding water could be dangerous and life threatening in long durations. It seems that football players are more susceptible to heat illnesses because they have “double days” usually during the hottest part of the year. The double days often take place in the beginning of summer after a long summer break where athletes have not been practicing and have lost any acclimatization to exercise and heat that they had before. Therefore, the athletes are more likely to suffer from some form of heat illness during the first few weeks of practice. “During prolonged work periods in the heat, the maintenance of high sweat rates leads to progressive dehydration, which may be accompanied by impairment of mental and physical performance and of heat dissipation.” (Bates, & Miller, 2008). The combination of water and sports drinks seem to offer the best hydration. The sports drinks replenish sodium and other electrolytes that water does not have. However, only drinking sports drinks can provide too much salt and therefore, drinking water becomes necessary as well. “Ingestion of non-caffeinated sports drinks containing vital nutrients such as water, electrolytes and carbohydrates during exercise may help maintain physiological homeostasis, resulting in enhanced performance and/or reduced physiological stress on an athlete’s cardiovascular, central nervous and muscular systems. Both the volume of the rehydration fluid and its composition are critical in maintaining whole body fluid homeostasis.” (Snell, Ward, Kandaswami, & Stohs, 2010).

Proper clothing, equipment, and preparation are also key factors in preventing heat illness. “Heat production during exercise is 15 to 20 times greater than at rest, and is sufficient to raise a person’s core body temperature 1°C every five minutes, if there were no inherent regulatory mechanisms.” (Miners, 2010). It is important to drink fluids, monitor oneself and others and wear proper clothing. Players should be aware of how much fluid they drink and take note if they start to cramp or feel lightheaded. Players and coaches need to be sure to wear sunscreen and to reapply it accordingly. Lightweight, breathable clothing should be worn in order to allow air to flow and dissipate heat. Light-colored clothing should be worn when possible as the light colors reflect the sun’s rays where as darker colors such as black absorb the rays and thus intensifies the heat that the body is absorbing. Shorts and short-sleeved shirts should also be worn when possible to allow for as much breeze to flow to skin contact. This is the idea behind the recommendation of the National Athletic Trainer’s Association (NATA) and American College of Sports Medicine (ACSM) to acclimatize to the heat. It is especially important for football players in the early summer months to follow this safety guideline. It can take up to 14 days to acclimatize the body to the heat. So, it is important to start off with shorter practices during the early morning or later evenings. The players should start practices in shorts and short-sleeved shirts and build up to pads, then full pads, and then finally full pads with full uniform. It is also important to slowly increase the length of time the players practice and to modify which part of the day they are practicing in. Not only do the athletes need their proper equipment to help prevent heat illness, but the coaches and sports medicine team need their proper equipment as well. Ice water immersion has been identified as the best way to cool a person’s body rapidly and so a small pool-like container is needed on the sidelines of every sporting event. Coolers of ice and others with water should be kept next to the pool with the intent to use it only for the need of an emergency. Other coolers should be provided for drinking water. In some cases where a small pool-like container is not available, ice water buckets and towels should be available to cool an athlete. The sports medicine team should also supply a few tents to allow a place for athletes to escape from the sun. Although it may be an uncomfortable situation for the athlete and/or the athletic trainer, rectal temperature is the best way to determine core body temperature. Oral, tympanic, or other methods of reading a temperature are just not sufficient enough. They do not read a true core body temperature. Ingestible pills that read the body’s temperature are a great way to find out the athlete’s temperature for a few days, however, they are costly. The pills can be used to track an athlete’s body temperature, which is especially important for those who are susceptible to heat illnesses.

_Modifiable Risks_

Some of the things listed above in prevention techniques are also found in the modifiable risks category. Acclimatization to heat, dehydration, humidity, and high heat are all risks that can be modified, and thus, prevented. With proper education and planning, a heat acclimatization process can be initiated, proper hydration methods can be provided, and practices and games can be modified accordingly whether high heat, humidity, or other environmental factors occur. As mentioned above, the ACSM has set recommendations for acclimatization to heat but they also include information on hydration, humidity, and heat. “These recommendations consist of guidelines that measure heat stress and define the severity of heat stress by a Wet Bulb Globe Temperature (WBGT) Index. Based on the WBGT at the time of the event, the ACSM also has recommendations regarding the type, durations, and frequency of exercise regimes for a particular day, the frequency of hydration and rest breaks, and whether or not the activity should be moved to a different time of day or cancelled altogether.” (Cooper, Jr, Ferrara, & Broglio, 2006). Each sports medicine team should make their own policy based on these recommendations. Each employee should receive a copy and should sign a form acknowledging receipt and cooperation. The WBGT Index has become widely recognized and used as one of the best methods to determine whether it is safe to engage in physical activity outside or not. “WBGT is not air temperature, but is measuring the relative heat and humidity. It indicates web bulb globe temperature, an index of climatic heat stress that can be on the field by the use of a psychrometer…High WBGT indicates extreme risk of heat-related problems and appears to be one of the best predictors of heat illness.” (Cleary, 2007).

_Measuring Heat_

Another way to help determine whether it is safe to participate in physical exercise outside is by using one of the many heat index charts available to the public. A new one in particular, the Kleiner Exertional Heat Illness Scale (KEHIS), eliminates the many traditional categories of heat edema, heat cramps, heat, syncope, heat exhaustion and heat stroke and combines them to set three categories: mild, moderate, and severe. This scale is similar to the Glasgow Coma Scale in that it uses a points system to help determine which category the person falls into. Since not every person will have each sign or symptom found in the traditional categories, Kleiner felt this method of a point system would help identify the seriousness of the illness the athlete is suffering from. The points range from zero to 25. “A need exists for a universal scale that can objectively quantify the severity of heat-related illness. The KEHIS has been designed to fill that void. A KEHIS score of 12 is different than a KEHIS score of 15, and a score of 15 on one patient has the same level of urgency as a score of 15 in another. There is no disagreement about the level of severity.” (Kleiner, 2002). So, the WBGT and other heat index charts are used to determine whether it is safe to begin play and the KEHIS is used to determine which level of heat illness a person is experiencing. It is important to identify which level the athlete is experiencing because a severe, or heat stroke illness, is life threatening and needs to be treated immediately. It is also important to determine if an athlete is experiencing a mild or moderate heat illness. Heat illnesses are a continuum and one level can progress to the next very quickly.

### Considerations

Communication between medical team members is crucial when dealing with an emergency. The Certified Athletic Trainer (ATC) is usually the only medical personnel on the sideline for athletic events. In some cases a physician, physical therapist, and/or Emergency Medical Services (EMS) may also be present. One of the best ways for a medical team to effectively communicate during a medical emergency is by having an Emergency Action Plan (EAP) in place. Practice of the EAP is essential so that every person knows exactly what their job is in order to help eliminate confusion and chaos during the actual emergency. The EAP should specifically list every member of the medical team, their title, and contact information. Each venue; baseball field, soccer field, gymnasium, tennis courts, pool, etc., will need their own specific EAP established. Things included should be where to locate the ATC and emergency equipment such as Automated External Defibrillator (AED), splints, crutches, spine board, and bandages, to name a few. Communication lines such as cell phone, land lines, or 2-way radio with frequency and channel information, should also be noted. Also included in the venue section are directions for EMS to reach the specific facility. Details on who will call 911 and who will meet the ambulance when it arrives should also be included. This section should also have a list of all the area hospitals and directions so that they may be given to family members of those being transported. Other things to consider are environmental concerns such as thunderstorms, lightening, hail, hurricane, tornados, etc. For each of these situations, there needs to be a specific “safe location” for people to evacuate. Instructions for athletes to drop any metal equipment (bats, rackets, clubs, etc.) and for anyone to avoid metal stadium seating or tall trees are of utmost importance. The ATC will be in direct communication with the head coaches and officials and can suspend the game for safety reasons at any point.

With specific regards to heat illness injury, communication is crucial between members of the medical team. From the time the athlete suffers an attack, the ATC must put the EAP into action. After the athlete is released from the hospital, communication needs to be present between the athlete, athletic trainer, physician, coach, and in the case of a minor, the parents or guardians. Communication is crucial in order to provide the best care possible for the athlete.


Currently, there is no one set of standards for returning-to-play (RTP) after suffering a heat illness attack. Some commonly found suggestions include: 1) athlete suffered from heat cramps can RTP after hydrating until the cramps are gone, 2) athlete who suffered heat exhaustion should not RTP for 24 hours or more, and 3) athlete who suffered from heat stroke should stay out of activity for at least one week and must be cleared by a physician. “Recovery from EHI is typically determined by normalization of serum electrolytes, CK, creatinine, liver function tests, and normal mental status. When EHI victims meet these conditions, they can resume light to moderate exercise for 15 minutes daily. Maximal efforts, such as competitive running, and competitive sports, such as football, should not be permitted until recovery is complete. . . If the victim does not exhibit heat tolerance after three months post EHI episode, recommendations can be modified to an unrestricted exercise/workload, but maximal exertion, particularly during significant heat load conditions, should avoided.” (Muldoon, Deuster, Voelkel, Capacchione, & Bunger, 2008). Even though there are no set standards of returning an athlete to play, it seems wise to assure proper hydration and clear mental status as well as being cleared by a physician before allowing the athlete to compete. The timeline of RTP widely varies depending on the type of heat illness suffered and varies from athlete-to-athlete. As far as I, a medical professional, am concerned, we need to establish a professional standard for returning athletes back to practice and competition.

_Special circumstances_

There are many special circumstances to consider when dealing with heat illnesses. Amateur athletes, older athletes, and “weekend warriors” are of major concern themselves. These athletes tend to be out of shape or far less active than the collegiate or professional athlete, and yet many expect to go out and perform just as well. They push themselves too far and often experience a myriad of injuries and illnesses as a result. “Amateur participants may not have a complete understanding of recommended strategies for handling outdoor extreme conditions like heat and humidity. Thus, heat-related illnesses like heat stress and eventually heat stroke become increasingly possible, with susceptibility increasing with age, vulnerability factors like co-morbidity (e.g., chronic diseases), and various health-related behaviors (e.g., nutrition, hydrations, and sleep or rest).” (Shendell, Alexander, Lorentzon, & McCarty, 2010).

When thinking of athletes, many think of sports that take place on land. However, athletes who compete in or on the water are also of concern. Just because the athlete is in or on the water does not mean that they should be treated any differently than the land athlete. With regards to those athletes on the water, “paddlers should be encouraged to drink to thirst and replace electrolytes during long distance races and frequently be assessed for signs and symptoms of heat illness to prevent life threatening increases in body temperature and heat stroke. Paddlers should aggressively seek sun protection and have lacerations and skin injuries properly cleaned and evaluated by medical personnel if there are signs of infection.” (Haley, & Nichols, 2009).

On the other end of the spectrum are those who may have other health issues, thus, making them even more susceptible to exertional heat illnesses. Some researchers believe that there may be a link between exertional heat illness with those who have exertional rhabdomyolysis (ER), malignant hyperthermia (MH), and/or menstrual cycles. While exertional heat illness can be described as someone who has extreme high core body temperature, impaired mental status, and possible musculoskeletal or organ damage, a person with malignant hyperthermia does as well. Both EHI and MH are also both found in otherwise healthy people. Some of the people, who suffered from what appeared to be EHI, were later found to actually have been malignant hyperthermia. In contradiction, ER can also occur in warm or cool environments. However, like EHI and MH, “ER also is a hypermetabolic state wherein the skeletal cell membrane is severely compromised and serum CK values are markedly increased.” (Muldoon, et al, 2008). The recovery process of each of these seems to be very similar in that it calls for normalization of CK, serum electrolytes, creatinine, and liver functions. As of 2008, there are no biochemical tests, genetic tests, or functional bioassay tests available to determine the differences between the three. Further research is needed in order to be able to identify the similarities, differences, and treatments for each. In addition, Muldoon mentioned that females are more susceptible to heat illnesses than males. While searching through other articles I ran across an article researching the physiological responses to the menstrual cycle. In this article it was shown that females had a longer time to exhaustion than expected but was thought that by extending their time to exhaustion they become more susceptible to injury or illness. “Given the difficulty in conducting clinical research into the development of heat illness, obtaining evidence of the theoretical increased susceptibility to heat illness during the luteal phase in females remains elusive; however, it is an area that warrants further investigation.” (Marsh, & Jenkins, 2002).

The last special circumstance to consider is that of actually warming up before an activity while wearing an ice vest. The ice vest warm up was used on runners in a long distance race. The results showed that although heart rates varied, a lower body temperature was a consistent result. “The ice vest slowed the increase in core temperature throughout cross-country warm-up and racing among the participants of this study. With the reduced thermal strain, greater blood flow may be available for transport of oxygen to muscle. Sweat rate will likely be decreased during performance when the ice vest is used during the warm-up, and with a decreased sweat rate, blood volume should be better maintained, improving oxygen delivery to muscles. The greater blood flow and blood volume should lead to a better performance.” (Hunter, Hopkins, & Casa, 2006). While it is a fairly new idea, the ice vest warm up seems to provide impressive results. If we can decrease the core body temperature before an athletic event, it will theoretically, take longer for an athlete’s core body temperature to rise to a dangerous level. I found this article of interest because I am an athletic trainer in southern California where heat illnesses seem to be on the rise.

### Conclusions

In conclusion, the hope of this paper was to provide insight to how serious heat illnesses can be and how easy it is to prevent them. Currently, it seems that not enough people are knowledgeable of heat illnesses and the danger they possess. I urge everyone to take the time to learn about the prevention, treatments, and possible outcomes of heat illnesses. Learning this information could save a life. Even after years of education and research on heat illness, more and more athletes are suffering and dying from heat stroke. It is currently the second most leading cause of death in high school athletes and I find that totally unacceptable. The research and information on heat illness is out there for the public, however, they seem unaware of it. Medical professionals need to find a way to educate the public about heat illnesses, whether it is for the athlete or just a regular person.

### Applications in Sport

The mild versions of heat illness include: heat edema, heat rash, heat syncope, and heat cramps while heat exhaustion and heat stroke are much more serious and can lead to death. Parents and athletes need to be educated about the risks of playing sports, including environmental factors such as heat and humidity. Athletes also need to be aware of proper hydration methods to keep themselves healthy. The parents, athletes, coaches, and sports medicine team need to be on the same page with regards to the athletes’ safety and well being. Things like acclimatizing to the heat over a period of at least two weeks, proper hydration techniques, wearing proper, light-colored, breathable clothing, and identifying any underlying health issues before the start of the season are all important factors in helping to prevent heat illnesses. The sports medicine team is ultimately responsible for the safety of the athletes and must provide proper equipment, like a small pool with coolers of ice and water, for use of an ice water-immersion in the event of a heat related emergency. Communication between athletes, coaches, parents, and the sports medicine team are a necessity. An emergency action plan needs to be in place and implemented should an emergency arise. The timeline of when an athlete can return to play is unclear, however, the participant should be properly hydrated, have a clear mental status and should be cleared by a physician before returning to competition. There are always athletes with special circumstances or underlying health issues and it is important to try to identify these before the sport season begins so appropriate planning can be done regarding those issues. Further research is needed in the distinction between exertional heat illness, exertional rhabdomyolysis, and malignant hyperthermia. Additional information is also sought for those with menstrual cycles and the effect of possible heat illnesses. Warming up with an ice-vest also seems like it could be beneficial to the athlete, however, I believe additional research is still needed.

### Acknowledgments


### References

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