Generally associated with core temperatures >40°C (>104°F), though heat stroke can occur at lower core temperatures.
Diagnosis rests on the observation of hyperthermia in the presence of profound CNS dysfunction.
Medicines 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 multi-system 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 hyperthermia in the setting of CNS dysfunction. The core temperature with heat stroke is >40°C (>104°F), and typically ranges from 40°C to 44°C (104°F to 111.2°F), although higher core temperatures have been reported. Heat stroke can however occur at lower core temperatures. It should be suspected in the setting of high heat stress, through either exertion or environmental factors.
Heat exhaustion is a milder form of heat illness, where profound CNS disturbance is absent. In this case the core temperature is elevated (37°C to 40°C [98.6°F to 104°F]) but to a smaller extent than in heat stroke.
History and exam
- serum electrolytes
- liver function tests (LFTs)
- metabolic profile
- renal function tests
- creatine kinase (CK)
- PT, activated PPT, and INR
- lactic acid
- chest x-ray
- arterial blood gas
- medicine/toxicology screen
- thyroid function tests
- plasma glucose
Tufts University School of Medicine
JLG declares that he has no competing interests.
University of Michigan Congenital Heart Center
MB declares that he has no competing interests.
Department of Physiology
JM declares that he has no competing interests.
Department of Emergency Medicine
Mount Sinai School of Medicine
PH declares that he has no competing interests.
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