What should you know about extreme heat exhaustion?

Heat exhaustion occurs when heat exposure and fluid or salt loss overwhelm the body's ability to cool itself. Heavy sweating, weakness, headache, dizziness, nausea, thirst, clammy skin and a fast pulse may occur. Dark urine can suggest fluid depletion. Dehydration can contribute, and heat intolerance may make hot conditions harder to tolerate.

Heat exhaustion can progress to heatstroke. Confusion, unusual behaviour, loss of consciousness, seizures or very hot skin are danger signs that need emergency treatment rather than home observation.

Move the person to shade or air conditioning and stop activity. Remove excess clothing, loosen tight layers, and cool the skin with wet cloths, a fan or cool water. If fully awake and able to swallow, give frequent small sips of cool water or an oral rehydration drink. Stay with them and avoid alcohol or strenuous activity while recovering.

Call emergency services if the person becomes confused, faints, has a seizure, cannot drink, vomits repeatedly, has worsening symptoms or does not improve promptly with cooling. Treat suspected heatstroke as an emergency. Babies, older adults, pregnant people and those with heart, kidney or other long-term conditions should be assessed early.

Could medicines or a health condition increase my heat risk? How should I replace fluids safely? When can I return to work, exercise or outdoor activity, and which symptoms should prompt a same-day review?