Heat stroke in humans

Heat stroke can follow strenuous activity or develop during prolonged environmental heat. The person may have a very high body temperature, headache, dizziness, nausea, hot skin, rapid breathing or a fast heartbeat. The defining concern is a change in brain function, such as confusion, unusual behaviour, drowsiness, loss of coordination or seizure.

Heat exhaustion is a milder heat illness, but it can progress if the person remains hot or cannot replace fluid. A fever from infection is different from heat stroke, although both can raise body temperature and require careful assessment.

Call emergency services as soon as heat stroke is suspected. Move the person out of the heat, remove unnecessary clothing and cool the skin rapidly with cold wet cloths, water spray, ice packs wrapped in fabric or a fan. Keep cooling while waiting for help.

Place an unconscious person on their side and check breathing. Do not give food, drinks or medicines to someone who is confused, vomiting, drowsy or unable to swallow safely, because they may choke. Do not leave them alone.

Confusion, fainting, seizure, collapse, severe weakness or altered behaviour after heat exposure should be treated as an emergency, even if the person begins to look better. Emergency clinicians may provide monitored cooling and IV Fluid Therapy while checking for organ complications.

After recovery, ask what triggered the episode, whether medicines or health conditions increased risk, how to return to work or exercise, and which symptoms should prompt immediate help during future heat exposure.