Heat illness in the emergency department: keeping your cool.

Heat illness spans a broad spectrum of disease, with outcomes ranging from benign rash to fatal heat stroke. Heat illness is broadly divided into 2 types: classic and exertional. Both types occur as a result of exposure to elevated temperature with inadequate thermoregulation; however, classic illness occurs without preceding physical activity. Treatment consists of rapid cooling, fluid replacement, and physiologic support. Other milder forms of heat illness include heat fatigue, heat syncope, heat edema, and heat rash. Drugs, drug combinations, drug side effects, and infections can also cause or complicate heat illness and these manifestations may not respond to standard cooling maneuvers and treatments alone; each requires specific additional therapy or antidotes to reverse the cycle of heat and organ damage. This review examines the physiology, diagnosis, and treatment of exertional, classic, and drug-induced hypothermia. Field and prehospital diagnosis and treatment are also reviewed, with recommendations for rehydration and monitoring in rhabdomyolysis.