Exertion-induced heat stroke in a military setting

Heat stroke is a medical emergency characterized by sudden loss of consciousness and by failure of the heat-regulating mechanism, as manifested by high fever (usually above 104 degrees F) and cessation of sweating. Fatality rates for patients with heat stroke can vary from 0% to more than 40%. Immediately after heat stroke has occurred or is suspected, aggressive cooling measures should be initiated. This case illustrates a 24-year-old commissioned officer who developed heat stroke while running in PT formation dressed with shorts and a T-shirt. Although this patient was in good shape and the wet bulb was only 74.4 degrees F, he developed the classic symptoms of heat stroke, with a core temperature of 105.9 degrees F. He further developed hepatic and skeletal muscle enzyme abnormalities (SGOT, 4680; CPK, 327; LDH, 821) with hyposphosphatemia (0.8). This patient had no significant risk factors, and after the appropriate treatment, his enzyme abnormalities returned to normal without sequelae. This paper will discuss symptoms, predisposing factors, complications, treatment, and prevention of heat stroke--a topic that is important to all military physicians, especially to those deployed to hot, humid environments.