Heat Illness in Athletes

Abstract & Commentary

Synopsis: Sports medicine practitioners must be able to differentiate exercise-associated muscle (heat) cramps, heat syncope, exercise heat exhaustion, exertional heat stroke, and exertional hyponatremia to reduce the severity of heat illness in athletes.

Source: Binkley HM, et al. Journal of Athletic Training. 2002;37:329-343.

This statement provides preventive strategies to reduce heat-related illness, identifies the factors associated with early detection of heat illness, provides guidelines for on-site first aid and emergency management, and discusses return-to-play procedures. The thermoregulation and physiologic response to heat are reviewed, and the special concerns associated with special populations, such as children, older adults, and athletes with spinal cord injuries are discussed.

The statement points out that the traditional classification of heat illness includes heat cramps, heat exhaustion, and heat stroke, but that this system omits several other heat- and heat-related illnesses. In this statement, exertional heat illnesses are defined under the categories of exercise-associated muscle (heat) cramps, heat syncope, exercise (heat) exhaustion, exertional heat stroke, and exertional hyponatremia. The signs and symptoms of each illness are presented and guidelines for treatment discussed.

Strategies for prevention of exertional heat illness include education of athletes and coaches, a thorough preparticipation medical screening, appropriate adaptation (acclimatization) to exercise in the heat, and proper sleep in a cool environment. The environmental conditions should be checked, and appropriate guidelines for participation, modified participation, or cessation of activity in extreme heat and humidity should be developed. Adequate and unrestricted access to water by athletes is essential, and high-risk athletes should be weighed before and after practice to monitor water lost and replaced. An emergency plan for treatment of heat illness should be developed and implemented prior to the start of practice.

Comment by David H. Perrin, PhD, ATC

This statement, supported by 230 references from the scientific literature, is an excellent resource for physicians and allied health care providers involved in the prevention, recognition, and treatment of athletic injuries and illnesses. It provides the relevant physiology of thermoregulation in support of the definitions of exertional heat illness, and the recommendations for prevention, recognition, and treatment of these illnesses.

The statement discusses the nonenvironmental and environmental risk factors associated with heat illness, and lists the predisposing medical conditions that add to the risk of heat illness. An understanding of this information is essential for the prevention of exertional heat illness and the establishment of appropriate guidelines for safe return to competition.

The need for appropriate guidelines in the care of competitive athletes at the high school, intercollegiate, and professional sport levels is obvious. One should be mindful that special populations of physically active individuals have special needs with regard to prevention and treatment of heat illness. For example, the physiology of prepubescent children, older adults, and spinal cord injured athletes may predispose them to exertional heat illnesses. The statement identifies some of the physiological factors and correctly identifies the need for additional research with these special populations.

Each form of heat illness is serious, but the elevated core temperature (> 40°C or 104°F) associated with exertional heat stroke is life threatening and can be fatal if not promptly recognized and treated. The statement explains that contrary to some common misconceptions, the fastest way to decrease body-core temperature is immersion of the trunk and extremities into a pool or tub filled with cold water between 1°C (35°F) and 15°C (59°F).

To obtain a copy of this position statement on exertional heat illness, contact: National Athletic Trainers’ Association, Communications Department, 2952 Stemmons Freeway, Dallas, TX 75247.

Dr. Perrin, Dean, School of Health and Human Performance, University of North Carolina—Greensboro, is Associate Editor of Sports Medicine Reports.