Heat rash

What is it? What are the symptoms? What are the treatments?

What is heat rash?

Heat rash, also known as prickly heat or miliaria, is a red rash of small spots that feels like prickling or stinging across the skin. It's common in babies and children, because their sweat glands aren't yet fully developed so they can't control their own body temperature properly, and symptoms usually occur when excessive sweat is produced. It's also common in overweight people, bedridden patients and mums-to-be.

When you sweat more than usual, sweat glands can get blocked, trapping sweat under the skin. The result is the prickling sensation and a red rash, which can crop up anywhere on your body, although it's most likely to appear where you have most sweat glands - so the face, neck and shoulders -and in skin creases where sweat accumulates.

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What are the symptoms of Heat rash?

A red rash that feels as if the skin is prickling or stinging. It's not only triggered by hot weather conditions, but can happen all year round.

What are the treatments and remedies of Heat rash?

No treatment is usually necessary for heat rash, which will clear up on its own. It will help if you take measures to cool the skin by removing some clothes. An electric fan can be helpful, too. If the rash is still there after 12 hours – especially in a baby or child – see your doctor urgently as rashes may be signs of other illnesses. If you are worried about the rash, perform the "tumbler test" by pressing a glass onto the rash. If the rash does not disappear with pressure, seek urgent medical help.

This guide 

The information in this Bounty A-Z of Family Health is not a substitute for an examination, diagnosis or treatment by a doctor, midwife, health visitor or any other qualified health professional. If in doubt, always speak to a doctor.

Bounty will not be held responsible or liable for any injury, loss, damage, or illness, however this occurs or appears, after using the information given on this website and in particular the A-Z of Family Health.

Further help

For health advice and information 24 hours a day, 365 days a year, the NHS offers call and web services. You can also visit NHS websites for services, health information and health news at nhs.uk 

  • England – call 111 from any landline or mobile phone free of charge, or visit nhs.uk 
  • Scotland – call 111 from any landline or mobile phone free of charge, or visit nhs24.com 
  • Wales – call 0845 4647 , or visit nhsdirect.wales.nhs.uk 
  • Northern Ireland – visit hscni.net


Heat rash