Heat exhaustion and heatstroke

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
  • a high temperature of 38 degrees Celsius or above
  • being very thirsty

The symptoms are often the same in adults and children. But 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:

  1. Move them to a cool place.
  2. Get them to lie down and raise their feet slightly.
  3. Get them to drink plenty of water. Sports or rehydration drinks are OK.
  4. 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 or 112 and look for an ambulance 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 while feeling too hot
  • a high temperature of 40 degrees Celsius 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.

Preventing heat exhaustion and heatstroke

There's a high risk of heat exhaustion or heatstroke during hot weather or exercise.

To help prevent heat exhaustion or heatstroke:

  • drink plenty of cold drinks, especially when exercising
  • take cool baths or showers
  • wear light-coloured, loose clothing
  • sprinkle water over your skin or clothes
  • avoid the sun between 11am and 3pm
  • avoid excess alcohol
  • avoid extreme exercise

This will also prevent dehydration and help your body keep itself cool.

Keep an eye on children, the elderly and people with long-term health conditions like diabetes or heart problems. They're more at risk of heat exhaustion or heat stroke.


Content supplied by the NHS and adapted for Ireland by the HSE

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

Page last reviewed: 22 July 2021
Next review due: 22 July 2024