Sports Medicine: Exertional Heat Illness

Exertional heat illness (EHI), specifically exertional heat stroke (EHS), is one of the three leading causes of death in young athletes. In the United States, the incidence of EHI appears to be increasing. The human body has multiple mechanisms to dissipate heat, including conduction, convection, radiation, and evaporation via perspiration. Limitations on heat dissipation occur in hot and humid weather and are increased during intense exercise. Dehydration further decreases ability to tolerate heat, and these factors increase the risk of EHI. EHI is a spectrum of conditions based on severity. The severity of a heat illness may not be apparent initially. Morbidity and mortality are related directly to the duration of body temperature elevation. Effective management requires rapid cooling of the body, optimally with cold water immersion of the patient, initiated as soon as possible. After cooling has achieved a reasonable temperature (ie, approximately 39°C [102.2°F]), the patient should be transported to the closest emergency department. Subsequent management depends on recovery time and potential late complications, including rhabdomyolysis and organ damage. After an EHI, athletes should not perform significant physical activity for at least 7 days. Prevention is based on acclimatization and maintenance of adequate hydration.