Heat stroke, a true medical emergency, is defined classically as the triad of altered mental status, elevated core temperature (> 40°C), and anhydrosis.1 The patient may be partially cooled in transport, however, and anhydrosis may not be a finding for a variety of reasons. Heat exhaustion is a vague syndrome, characterized by dizziness, weakness, fatigue, nausea, headache, myalgias, and variable core temperatures (from normal to 40°C), but the mental status of the patient is normal. Both heat exhaustion and heat stroke cause an elevation of hepatic transaminase enzymes, but the rise seen in heat stroke tends to be more extreme.
- Heat stroke patients always present with altered mental status.
1. Walker J, Barnes SB, Heat emergencies. In: Tintinalli JE, Kelen GD, Stapczynski JS, editors. Emergency medicine: a comprehensive study guide. 5th ed. New York: McGraw-Hill; 2000:123942.
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