Heatstroke is caused by a failure of the thermostat in the brain
which regulates the body temperature. If someone has a high fever
or has been exposed to heat for a long time, then their body can
become dangerously overheated.
Someone can also get heatstroke after using drugs such as
Sometimes, people get heatstroke after suffering from heat exhaustion. When someone gets too
dehydrated they stop sweating which means their body can’t cool
down anymore, so they develop heatstroke.
Heatstroke can develop with very little warning, causing
unresponsiveness within minutes of someone feeling unwell. Your
priority is to cool them down as quickly as possible and get
them to hospital.
Watch our video - heatstroke
What to look for - heatstroke
These are the six key things to look for:
- 1. Headache, dizziness and discomfort
- 2. Restlessness and confusion
- 3. Hot flushed and dry skin
- 4. A fast deterioration in the level of response
- 5. A full bounding pulse
- 6. Body temperature above 40°C (104°F)
What you need to do - heatstroke
• Quickly move them to a cool place and remove their outer
clothing but ensure you maintain their dignity.
• Then call 999/112 for an ambulance.
• Wrap them in a cold wet sheet and keep pouring cold water
over it until their temperature falls to at least 38°C (or
100.4°F). Measure this with a thermometer under their tongue or
under their armpit.
• If you can’t find a sheet, fan them or sponge them down
with cold water to keep them cool.
• Once their temperature seems to have gone back to normal,
replace the wet sheet with a dry sheet.
• While waiting for help to arrive, keep checking their
temperature, as well as their breathing, pulse and level of
• If they start getting hot again, repeat the cooling
process to lower their temperature.
• If they lose responsiveness at any point, open their
airway, check their breathing and prepare to treat someone who’s