Heat rash

Last updated:

Reviewed by:

Dr Bryony Henderson

, Lead GP at Livi

Medically reviewed

Heat rash or prickly heat is a skin condition caused by excessive sweating and can be very uncomfortable. Learn what to look out for and how to manage your symptoms.

What is heat rash?

In hot weather, your body makes sweat to help lower your core body temperature. In some cases, the sweat glands or ducts can become blocked, trapping sweat under the skin. The trapped sweat causes a rash to develop. Heat rash affects both children and adults. It’s not an infection and it can not be passed from person to person.

What are the symptoms of heat rash?

The symptoms of heat rash can include: 

  • Small, raised bumps that can appear anywhere on the body, including the face

  • A rash that often looks red on lighter skin tones and white or grey on darker skin tones

  • An itchy or prickly feeling

What causes heat rash?

Sweating is the main risk factor for heat rash. It may be caused by:

  • Hot or humid weather

  • A high fever

  • Tight clothing or a transdermal patch that covers the skin

  • Intense exercise

  • Medications or medical conditions that cause excess sweating

Heat rash in babies and children

People of all ages get heat rash, but babies are particularly prone because their sweat ducts are still developing. Heat rash can appear anywhere on a baby’s body but is most likely to appear in the folds of the skin and in areas where clothing can rub, like the neck and nappy area.

How is heat rash treated?

The best way to treat heat rash is to stop sweating as much as possible:

  • Stay in a cool area or room

  • Wear loose, breathable clothing like cotton

  • Stay well hydrated 

  • Keep the skin dry

  • Exfoliate your skin and remove bandages or patches if possible

  • Take cool baths or showers

Heat rash can cause an uncomfortable prickly feeling. To help relieve the discomfort:

  • Gently tap or pat the rash 

  • Cool the skin with a damp cloth 

  • Avoid perfumed skin products

When should I talk to a doctor?

Book an appointment to speak to a doctor if:

  • The heat rash does not improve after a few days

  • You’re worried or have any concerns about your baby’s rash

How can Livi help?

A Livi healthcare professional will be able to look at the rash and advise you of the possible causes. If your baby is aged over 12 months old, they can be seen by a Livi GP but if they’re unwell, it’s important to seek a face-to-face appointment for them to ensure there are no other causes of the rash. A GP can give you advice and might recommend a cream or tablet if the heat rash isn’t getting better on its own.

Last updated:
Reviewed by:
Dr Bryony Henderson, Lead GP at Livi