This NHS content is written for people in England. Services, entitlements and contact routes may differ in other countries.
Symptoms of heat rash
The symptoms of heat rash are:
- small, raised spots
- an itchy, prickly feeling
- mild swelling
The rash looks red on white skin. It may be harder to see or look grey or white on brown or black skin.
The symptoms of heat rash are often the same in adults and children.
It can appear anywhere on the body and spread, but it cannot be passed on to other people.
Heat rash appears as raised spots that are 2mm to 4mm across. Some spots may be filled with fluid.
Heat rash may be harder to see on brown or black skin. The spots may look grey or white.
How you can treat heat rash yourself
If you have heat rash the main thing to do is keep your skin cool so you do not sweat and irritate the rash.
To keep your skin cool
- Wear loose cotton clothing.
- Use lightweight bedding.
- Take cool baths or showers.
- Drink plenty of fluid to avoid dehydration.
To calm the itching or prickly feeling
- Apply something cold, such as a damp cloth or ice pack (wrapped in a tea towel), for up to 20 minutes.
- Tap or pat the rash instead of scratching it.
- Do not use perfumed shower gels or creams.
A pharmacist can help with heat rash
Speak to a pharmacist about heat rash. They can give advice and suggest the best treatment to use.
A pharmacist might recommend:
- calamine lotion
- antihistamine tablets
- hydrocortisone cream – though not for children under 10 as you'll need to get advice from a doctor before giving them this treatment
See a GP if:
- you have heat rash that does not improve after a few days
- your baby has a rash and you're worried
Causes of heat rash
Heat rash is usually caused by sweating a lot.
Sweat glands get blocked and the trapped sweat leads to a rash developing a few days later.
Babies often get heat rash because they cannot control their temperature as well as adults and children can.
Heat rash (prickly heat)
Heat rash (prickly heat)
Heat rash (prickly heat)
Heat rash causes small, itchy raised spots anywhere on the body.
You can ease heat rash by keeping your skin cool. A damp cloth, ice pack (wrapped in a tea towel) or medicines from a pharmacy can help any itchiness.
Heat rash can happen if your sweat glands become blocked and sweat gets trapped in them.
Content supplied by the NHS website, refreshed 19 August 2026. View the original NHS article ↗
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