First aid for someone who may have heat exhaustion or heatstroke

First aid advice for someone with heat exhaustion or heat stroke. Find out the symptoms, how to spot the early signs, and what treatment they may need.

Last updated 15 July 2022

First aid advice for someone with heat exhaustion 

Someone with heat exhaustion might have been in the sun or heat for a long time. They might look ashen, have a headache or dizziness, and feel sick. 

Learn first aid for a baby or child

We also have specific advice for first aid for a child who may have heat exhaustion.

What you should do if you think someone has heat exhaustion:

1. Help the person to a cool place and get them to rest.

Heat exhaustion happens when someone loses too much fluid and salt usually from sweating in hot conditions. 

2. Give them plenty to drink

Drinking water will replace lost fluids. If you have them, isotonic sports drinks will help replace salts lost through sweating.

3. Seek medical advice

Even if the person appears to recover fully, you should seek medical advice. If their condition gets worse, call 999 for emergency help.  

Common questions about first aid for someone who has heat exhaustion:

What are the signs of heat exhaustion? 

What is heatstroke?  

What are the signs of heatstroke? 

What do I do if someone has heatstroke?

What's the advice for someone who is pregnant during hot weather?

What's the advice for older people during hot weather?

What's the advice for someone with a medical condition during hot weather?


What are the first signs of heat exhaustion in an adult? 

If you think someone has heat exhaustion they may show the following signs or symptoms:

  • dizzy or confused, and complaining of headaches or cramps
  • sweating, with cooler skin to the touch
  • paler than usual - depending on your skin tone, this could mean your skin looks ashen, grey or a more yellowish hue. It might be easier to notice this change in colour on the palms of hands, nails, eyes, gums or tongue.
  • feel nauseous, with fast breathing and heart rate 

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What is heatstroke? 

Heatstroke occurs when someone becomes so hot it causes a failure of the brain’s thermostat, leading to the body becoming dangerously overheated. It is an emergency and needs medical help urgently. 

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What are the signs of heatstroke in an adult? 

If you think someone has heatstroke they may show the following signs or symptoms: 

  • have hot, flushed, and dry skin  
  • have a headache, feel dizzy, or be confused and/or restless  
  • rapidly worsening condition leading to being unresponsive 
  • body temperature over 40°C

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What you should do if you think someone has heatstroke: 

Call 999 immediately or ask someone else to do it.  

Quickly move them into a cool environment and remove outer clothing. Loosely wrap the person in cold damp clothes or a sheet. Continuously pour cold water over the sheet or clothes. If there is no sheet available, you can also fan them or sponge them with cold water.  Keep cooling them while waiting for help to arrive 

If their temperature returns to normal and they no longer feel hot to touch, you can stop cooling them. Replace the wet sheet with a dry one and help them to rest. 

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What is the advice for someone who is pregnant during hot weather?

The advice for dealing with hot weather is the same for someone who is pregnant, but it's important to take extra care during times of extreme heat or a heatwave.

The risk of sunburn is great during pregnancy so it's important to wear sunscreen and avoid the sun when possible. Pregnant women are more prone to swelling in their hands and feet due to fluid retention, which gets worse in hot weather.

Pregnant women should make sure they rest in the shade, and if necessary to cool their hands and feet in cool water. The increased demand on the circulatory system, also means it's even more important to maintain good levels of hydration.

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What is the advice for elderly people during hot weather?

The advice for heatstroke and heat exhaustion is the same for an elderly person, but they may be less able to adjust to the extremes of temperature. Pre-existing medical conditions can also complicate or worsen their response to hot weather.

The actions to take in the hot weather are the same as for everyone else such as keeping out of the sun, staying covered, keeping well hydrated, and making sure there is adequate ventilation. However, they may not be able to do these things for themselves so will need extra help from friends, family, or neighbours. Remember to look out for others in hot weather and check if they need assistance with anything to help them stay safe.

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What is the advice for those with medical conditions during hot weather?

People with medical conditions such as diabetes, obesity, or limited mobility are more vulnerable to the effects of heatwaves and hot weather, but the advice for specific conditions remains generally the same.

Anyone with a medical condition should be advised to follow advice from medical professionals and to seek medical aid if concerned.

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