What should you know about heat stroke?

The body becomes dangerously overheated and the brain and other organs can stop working normally. Warning signs include confusion, unusual behaviour, collapse, a seizure, severe weakness, hot skin, and a very high body temperature. Sweating may be present or absent, so the absence of sweat does not rule it out. Heat exhaustion can worsen into heat stroke, especially after prolonged heat, exertion, dehydration, or limited ability to cool down. Fever from infection is a different process, although both can make someone feel hot.

Call emergency services and move the person to a cool place. Remove unnecessary outer clothing and cool the skin with cool wet cloths, water spray, fanning, or ice packs wrapped in cloth at the neck, armpits, and groin. Stay with them and monitor breathing. Do not give fluids to someone who is confused, vomiting, having a seizure, or unconscious, and do not delay help while trying home treatment. Hospital care may include IV fluid therapy and active temperature control.

Treat suspected heat stroke as an emergency whenever overheating is accompanied by confusion, fainting, seizure, severe drowsiness, collapse, or inability to drink safely. Emergency assessment is also needed when symptoms continue or worsen after moving to a cooler setting. A person who has vomited repeatedly, cannot keep fluids down, or has signs of shock needs urgent medical attention.

After recovery, ask what may have contributed, how to plan cooling and hydration during heat, when it is safe to return to exertion, and whether medicines or health conditions raise your risk.