Heat rash (prickly heat)

Heat rash is uncomfortable but usually harmless. It should clear up on its own after a few days.

Check if you have heat rash

The symptoms of heat rash are:

  • small red spots
  • an itchy, prickly feeling
  • redness and mild swelling

The symptoms are often the same in adults and children.

It can appear anywhere on the body and spread, but it's not infectious to other people.

If you're not sure it's heat rash

Look at other rashes in children.

How you can treat or prevent heat rash yourself

The main thing to do is keep your skin cool so you don't 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 rash

  • apply something cold, such as a damp cloth or ice pack (wrapped in a tea towel) for no more than 20 minutes
  • tap or pat the rash instead of scratching it
  • don't 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 – for example, if you're pregnant or a child has the rash.

They might recommend:

  • calamine lotion
  • hydrocortisone cream – but not on the face
  • antihistamine tablets – but speak to a pharmacist first as these aren't always appropriate

See a GP if:

  • the rash doesn't improve after a few days
  • your baby has a rash and you're worried

Causes of heat rash

Heat rash is usually caused by excessive sweating.

Sweat glands get blocked and the trapped sweat leads to a rash developing a few days later.

Babies often get it because they can't control their temperature as well as adults and children can.

Page last reviewed: 09/01/2018
Next review due: 09/01/2021

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