Heat exhaustion and heatstroke

Children don't sweat as much as adults. So they find it harder to stay cool. When its hot, you should make sure that babies and children drink enough fluids.

Heat exhaustion

Heat exhaustion is an illness that can happen in the heat.

Your child could get heat exhaustion if they become too hot and if they are not drinking enough fluids. 

Heat exhaustion can turn into heatstroke if the body cannot cool down within 30 minutes.


If heat exhaustion turns into heatstroke your child will need to be treated as an emergency.


Heatstroke is a life-threatening medical emergency.

Your child can get heatstroke if they are not able to cool their body down. Their body can get hotter and hotter. This causes their temperature to rise.

In severe cases this can cause brain damage. If your child has heatstroke they need to get treatment quickly. Treatment will help to bring their temperature down.

Children's bodies heat up much faster than adults' bodies. This is why children are more at risk of heat stroke.

Heat exhaustion and heatstroke can happen indoors as well as outdoors.  Any environment that is too warm can lead to these conditions, including in a car or near a window on a hot day.


Call an ambulance (999 or 112) if your child has one or more of the signs of heatstroke

Never leave a child in a car

A parked car can heat up by at least 10°C in just 10 minutes. Opening the window of a parked car does not help keep the inside of a car cool enough. Never leave a child in a car.

Internal organs start to shut down when the body's temperature reaches 40°C. Death can occur when it reaches 41.7°C.

Signs of heat exhaustion

The signs of heat exhaustion in children can include:

  • intense thirst
  • weakness or fainting
  • cramps in the arms, legs or stomach
  • no appetite, feeling sick or vomiting
  • irritability or being cranky
  • headache
  • sweating a lot
  • pale clammy skin
  • temperature of more than 38 degrees (but less than 40 degrees)

If your child has heat exhaustion

If you think your child may be suffering from heat exhaustion you should:

  • get them to rest in a cool place, ideally in a room with air conditioning, or at least somewhere that is in the shade
  • give them plenty of fluids to drink. This should either be water or a rehydration drink such as a sports drink. Avoid alcohol or caffeine as this can increase dehydration
  • cool their skin with cold water

When to call an ambulance 

Call an ambulance (999 or 112) if your child has one or more of the following signs of heatstroke:

  • They are no better 30 minutes after being treated for heat exhaustion.
  • Hot and dry feeling.
  • Your child isn't sweating even though they are too hot.
  • Severe headache.
  • Temperature of 40 degrees Celsius or above
  • Rapid breathing or being short of breath
  • Confusion
  • Has a fit (seizure)
  • Loses consciousness
  • Is unresponsive

While you wait for help to arrive there are a few things you can do:

  • Bring your child indoors if possible, or into the shade, away from the heat.
  • Undress your child and sponge their skin with cool water.
  • If your child is awake and acting normally, get them to drink a cold drink. If they are not fully awake or if they are very drowsy, do not try to force them to drink.

Preventing heat exhaustion and heatstroke

To help prevent heat exhaustion and heat stroke, make sure your child:

  • drinks plenty of cold drinks, especially when exercising
  • takes cool baths or showers
  • wears light-coloured and loose clothing - sprinkle water over skin or clothes
  • is in the shade from the sun between 11am to 3pm

Page last reviewed: 4 June 2019
Next review due: 4 June 2022