Heat stroke when there is no sweating

Sweating is one way the body releases heat, but it may reduce or stop as heat illness worsens. Some people with heat stroke continue to sweat, while others have hot, dry skin. The more useful warning signs are a change in thinking or behaviour, fainting, seizure, extreme weakness, headache, nausea or an inability to cool down. No sweating can also have unrelated causes.

Call emergency services, move the person out of the heat, remove excess clothing and cool the skin with wet cloths, fanning or a cool bath. Keep watching breathing and responsiveness. Do not delay care to measure temperature, and do not give anything by mouth to someone who is confused, drowsy or vomiting.

Treat confusion, collapse, seizure, severe headache, repeated vomiting, breathing difficulty or reduced responsiveness as emergencies after heat exposure. If the person remains unusually hot or weak despite cooling, get urgent assessment. Fever and medication effects can resemble heat illness, so a clinician may need to distinguish them.

Ask how to recognise heat illness in someone who takes medicines affecting sweating, has a chronic condition or works outdoors. Clarify cooling plans, hydration, warning signs and when normal activity is safe.