Heat stroke and stopping sweating: what to know

Sweating is one way the body releases heat. During severe heat illness, the body may no longer cool itself effectively, so skin can become hot and dry. However, dry skin is not required for heat stroke: sweating can continue, especially in humid conditions or during exertion. The more concerning clues are a change in thinking or behaviour, unusual drowsiness, fainting, a seizure, severe weakness, headache, nausea, or vomiting. Heat exhaustion can progress to heat stroke, so worsening symptoms should not be watched at home.

A thermometer reading can support concern, but do not delay help while trying to obtain an exact temperature. Heat stroke is a medical emergency because overheating can affect the brain and other organs.

Call emergency services if heat stroke is suspected. Move the person to shade or a cool, ventilated place, remove extra clothing, and cool the skin with cool wet cloths, water mist, or a fan. Place cold packs wrapped in fabric near the neck, armpits, and groin if available. Stay with the person and keep checking their breathing and responsiveness.

Do not give drinks to someone who is confused, vomiting repeatedly, having a seizure, or unable to swallow normally. Do not give alcohol. If the person is awake, alert, and swallowing safely, small sips of cool fluid may be reasonable while help is on the way, but fluids do not replace urgent assessment.

Seek emergency help immediately for confusion, unusual behaviour, fainting, a seizure, loss of coordination, or difficulty waking the person. Treat very hot skin with marked weakness, a severe headache, or repeated vomiting as urgent, particularly after time in high heat or strenuous activity. Do not wait for sweating to stop, and do not use the presence of sweating to rule heat stroke out.

While waiting, follow the emergency operator's instructions. Hospital care may include rapid cooling, monitoring, and treatment such as IV Fluid Therapy when clinically needed.

Ask what likely triggered the overheating, whether any medicines or health conditions increase heat risk, and when it is safe to return to exercise or outdoor work. Also ask which early symptoms should prompt a break in a cool place and how to replace fluids safely.