Heat exhaustion and heatstroke

Heat exhaustion is a warning that the body is struggling to stay cool. Heatstroke is a medical emergency: the body has lost control of its temperature. If someone is hot and confused, collapses or has a seizure, call your local emergency number (112 in Europe and many other countries, 911 in North America) and start cooling them at once.

Heat exhaustion

Signs: heavy sweating, pale and clammy skin, headache, dizziness, feeling sick, cramps, tiredness, fast pulse and intense thirst. They are still thinking clearly.

1. Move them somewhere cool and shaded.
2. Lie them down with their legs raised a little.
3. Loosen or remove extra clothing.
4. Give plenty of cool water to sip, or better, an oral rehydration drink or a sports drink.
5. Cool their skin with a wet cloth, a spray of water and a fan.

They should feel better within 30 minutes. If they don't, or get worse, treat it as heatstroke.

Heatstroke

Signs: very high body temperature (40 °C or more), hot skin that may be dry or sweaty, confusion, strange behaviour, slurred speech, fainting, seizures or unresponsiveness. Confusion in someone who is hot is the key warning sign.

Cool them as fast as you can — every minute matters:

1. Move them into the shade and remove most of their clothing.
2. Best: put them in cold water up to the neck, such as a bath, stream or lake, supporting their head so it stays clear of the water. Stay with them constantly.
3. If you can't do that: soak them with cold water, keep pouring it over them, and fan hard. Wrap them in wet sheets or towels and keep the sheets wet.
4. Put cold packs or ice wrapped in cloth on the neck, armpits and groin.
5. Keep cooling until they are clearly more alert or help arrives. Stop if they start shivering.

Only give drinks if they are fully alert and can swallow. If they become unresponsive but are breathing, put them in the recovery position. If they stop breathing normally, start CPR.

Who is most at risk

Babies and young children, older people, people with heart or lung conditions, anyone working or exercising hard in the heat, and people on certain medicines.

Prevention

• Drink regularly before you feel thirsty.
• Rest in the shade during the hottest part of the day.
• Wear loose, light-coloured clothing and a hat.
• Never leave anyone, or any animal, in a parked vehicle.
• Check on neighbours who live alone during heatwaves.

This guide does not replace a first-aid course. A few hours of hands-on practice will make you far more confident when it matters.

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