Heat stroke

Heat stroke is generally associated with core temperatures >104°F (>40°C).

Diagnosis rests on the observation of profound central nervous system dysfunction in the presence of hyperthermia.

Medications may predispose patients to heat stroke (e.g., diuretics, antihypertensives).

Early cooling reduces mortality and morbidity, and should be initiated as soon as possible.

Evaporation and ice water immersion are both widely used as cooling methods.

Patients are at risk of multisystem organ failure, so careful monitoring is essential even after return to normothermia.

This topic covers the management of both heat stroke and heat exhaustion in adults.

Heat stroke is defined as central nervous system (CNS) dysfunction in the setting of hyperthermia. It is associated with core temperature >104°F (>40°C), and typically ranges from 104°F to 111.2°F (40°C to 44°C), although higher core temperatures have been reported. It should be suspected in the setting of high heat stress, through either exertion or environmental factors. Heat stroke can occur at measured core temperatures <104°F (<40°C), either because of inaccurate measuring techniques or from effects of prior cooling.

Heat exhaustion is a milder form of heat illness, where profound CNS disturbance is absent. In this case the core temperature is elevated (98.6°F to 104°F [37°C to 40°C]), but to a lesser extent than in heat stroke.