What should you know about heat stroke?

Heat stroke can follow prolonged heat exposure or strenuous activity, especially when fluid loss and humidity make cooling difficult. The nervous system is affected early: a person may become confused, unusually drowsy, uncoordinated, agitated or unconscious. The skin may feel very hot and may be dry or sweaty. Headache, nausea, vomiting, a fast pulse and a fever-like temperature can occur. Heat exhaustion is less severe, but it can progress, so worsening mental state is a key warning sign.

Call emergency services immediately. Move the person to shade or a cool indoor place, remove excess clothing and cool the skin with water, wet cloths, fans or ice packs placed at the neck, armpits and groin. Stay with them and monitor breathing. Do not give drinks to someone who is confused, vomiting or unconscious, and never leave them alone in a hot vehicle. Hospital treatment may include IV fluid therapy and controlled cooling.

Treat suspected heat stroke as urgent even if the person seems better after cooling. Confusion, collapse, seizure, fainting, severe weakness, repeated vomiting or a very hot body require emergency assessment. Someone recovering from heat exhaustion should also be reviewed if symptoms do not settle with rest, cooling and fluids, or if symptoms return after activity.

How can I safely return to exercise after heat illness? Do my medicines increase heat risk? What cooling plan should my family use? Which symptoms mean emergency help is needed?