UMEM Educational Pearls

Category: Critical Care

Title: Heat Stroke? Time to Chill.

Keywords: heat stroke, critical care, acute kidney injury, seizures, neurological (PubMed Search)

Posted: 7/19/2011 by Haney Mallemat, MD
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Heat stroke is hyperthermia (>41.6 Celsius / 106 Fahrenheit) plus neurologic findings (e.g., altered mental status, seizures, coma, etc.); it also causes systemic inflammation response syndrome (i.e., cytokine release), coagulation disorders (e.g., thrombosis in end organs) and tissue abnormalities (e.g., acute kidney injury and rhabdomyolysis)

Two classifications exist:

  • Exertional heatstroke (young people engaged in strenuous physical activities in hot climates)
  • Non-exertional heatstroke occurring in sedentary people (elderly, debilitated, or chronically-ill patients) who are unprotected from the elements (e.g., trapped in apartments during heat waves)

Treatment includes:

  • Insertion of a continuous core thermometer
  • Supporting ABC’s
  • Cooling by at least to 0.2 degrees celsius per minute to 39 degrees (to avoid overshoot)
  • Benzodiazepines for sedation, shivering, and seizures
  • Antipyretics and phenytoin have not been shown beneficial
  • Support and protect end-organs with particular attention to kidneys; increased risk of kidney injury from rhabdomyolysis, ischemia and systemic inflammation.

Despite the most aggressive therapy, up to 30% survivors may have permanent neurologic or multi-organ system dysfunction months to years after recovery


Leon, L. Heat stroke: role of the systemic inflammatory response. Journal of Applied Physiology 2010 Dec;109(6):1980-8

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