Heat exhaustion is not usually serious if you can cool down within 30 minutes. If it turns into heatstroke, it needs to be treated as an emergency.

Check for signs of heat exhaustion The signs of heat exhaustion include: a headache

dizziness and confusion

loss of appetite and feeling sick

excessive sweating and pale, clammy skin

cramps in the arms, legs and stomach

fast breathing or pulse

temperature of 38C or above

being very thirsty The symptoms are often the same in adults and children, although children may become floppy and sleepy. If someone is showing signs of heat exhaustion, they need to be cooled down.

Things you can do to cool someone down If someone has heat exhaustion, follow these 4 steps: Move them to a cool place. Get them to lie down and raise their feet slightly. Get them to drink plenty of water. Sports or rehydration drinks are OK. Cool their skin – spray or sponge them with cool water and fan them. Cold packs around the armpits or neck are good, too. Stay with them until they're better. They should start to cool down and feel better within 30 minutes.

Immediate action required: Call 999 if: You or someone else have any signs of heatstroke: feeling unwell after 30 minutes of resting in a cool place and drinking plenty of water

not sweating even though too hot

a temperature of 40C or above

fast breathing or shortness of breath

feeling confused

a fit (seizure)

loss of consciousness

not responsive Heatstroke can be very serious if not treated quickly. Put the person in the recovery position if they lose consciousness while you're waiting for help.