Understanding Heatstroke Heatstroke is the most dangerous of the heat-related illnesses and can be fatal. Its exact cause is not known, but the result is marked hyperthermia that can produce widespread cellular damage if not treated immediately. Incidence and mortality figures for the athletic population are difficult to ascertain, but some have been reported. Undoubtedly, the incidence of nonfatal heatstroke was higher. This can be attributed in large part to improved initial management with early and aggressive cooling measures.
Heatstroke occurs in two forms, exertional and classic.
The classic version is recognized by the well-known triad of hyperpyrexia, anhidrosis, and mental status changes. Classic heatstroke generally occurs during heat waves and typically affects the very young, the very old, and those with chronic diseases like diabetes, congestive heart failure, or coronary artery disease. This form is the result of an exogenous heat load that overwhelms the body's ability to cope with it. In contrast, the athlete is at risk for the exertional form of heatstroke. The victim is not at the extremes of age and is usually free of chronic disease, and the occurrence is sporadic.