Heat Exhaustion and Heatstroke

Overview

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

What is heat exhaustion?

​Heat exhaustion occurs when your body overheats and loses excess amounts of water and salt, typically from sweating. 

What is heatstroke?

Heatstroke is caused by a failure of the ‘thermostat’ in the brain which regulates the body’s temperature. This means the body is unable to cool down when it becomes too hot. 

Heatstroke is a serious medical emergency.

It could be caused by spending too much time in the sun, having a high fever, or from taking non-prescription drugs such as Ecstasy. It can also occur after heat exhaustion when sweating ceases.​

Signs and Symptoms

The signs of heat exhaustion include:

• tiredness
• dizziness
• headache
• feeling sick or being sick
• excessive sweating and skin becoming pale and clammy or getting a heat rash, but a change in skin colour can be harder to see on brown and black skin
• cramps in the arms, legs and stomach
• fast breathing or heartbeat
• a high temperature
• being very thirsty
• weakness

The symptoms of heat exhaustion are often the same in adults and children, although children may become irritable too.

If someone is showing signs of heat exhaustion they need to be cooled down and given fluids.

Immediate First Aid Steps

Things you can do to cool someone down

If someone has heat exhaustion, follow these 4 steps:

1. Move them to a cool place.
2. Remove all unnecessary clothing like a jacket or socks.
3. Get them to drink a sports or rehydration drink, or cool water.
4. Cool their skin – spray or sponge them with cool water and fan them. Cold packs, wrapped in a cloth and put under the armpits or on the neck are good too.

Stay with them until they're better.

They should start to cool down and feel better within 30 minutes.

When To Seek Medical Help

Call an ambulance or seek immediate medical help (e.g. Emergency Department) if you or someone else have signs of heatstroke, including:

• still unwell after 30 minutes of resting in a cool place, being cooled and drinking fluids
• a very high temperature
• hot skin that's not sweating and might look red (this can be harder to see on brown and black skin)
• a fast heartbeat
• fast breathing or shortness of breath
• confusion and lack of coordination
• a seizure or fit
• loss of consciousness

Do not drive yourself to the Emergency Department. Ask someone to drive you or call an ambulance instead. The emergency operator should guide you on what to do while you wait for help.

Put the person in the recovery position if they lose consciousness while you're waiting for help.

Get medical help if:

• you or someone else have symptoms of heat exhaustion that you're struggling to treat or you need advice about

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 more cold drinks, especially if you're active or exercising
• wear light-coloured, loose clothing
• avoid the sun between 11am and 3pm
• avoid excess alcohol
• avoid extreme exercise
• if you're inside on a very hot day, close curtains, close windows if it's hotter outside than in your home and turn off electrical equipment and lights that get hot

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

Children, older people and people with long-term health conditions (such as diabetes or heart problems) are more at risk of heat exhaustion or heatstroke.