Tiny red bumps appear on your baby’s neck and chest after a warm day or a snug nap. It is often heat rash, also called prickly heat or miliaria. Heat rash in babies is common, because their sweat glands are still developing, and it usually fades quickly once your baby cools down. Here is how to spot it, treat it and prevent it.
Quick answer: heat rash in babies
- Looks like: tiny red or clear bumps, sometimes itchy, often in skin folds, the neck, chest, back or nappy area.
- Caused by blocked sweat glands when a baby is too warm.
- Treatment: cool your baby down and let the skin breathe; it usually clears in a few days.
- Prevent by avoiding overdressing and keeping rooms cool.
How to treat heat rash
- Move your baby somewhere cooler, out of the sun.
- Remove extra layers and dress them in loose cotton.
- Give a lukewarm bath or sponge the skin with cool water, then pat dry.
- Let the skin air-dry rather than covering it with thick creams.
- Offer extra feeds to keep your baby hydrated.
- Ask your pharmacist before using any cream for itching.
Preventing heat rash
- dress your baby in light, breathable layers
- keep the bedroom around 16 to 20°C and use a fan pointed away from the cot in hot weather
- avoid heavy blankets and do not overwrap
- keep your baby out of direct sun and use pram sunshades that allow air flow, not blankets
- check your baby’s chest or the back of the neck: it should feel warm, not sweaty
See the best sleep environment, sunscreen for babies and diaper rash in hot weather.
Heat rash or something else?
Heat rash appears in warm, covered areas and fades as your baby cools. A rash with fever, or one that does not fade when pressed with a glass, needs medical attention. See baby rashes.
When to talk to your doctor
- the rash does not improve within 3 to 4 days
- bumps fill with pus, or the skin becomes hot, swollen or painful
- your baby has a fever, or seems unwell or very sleepy
- a rash that does not fade under a glass: seek urgent help
- signs of overheating or dehydration, such as hot dry skin, fewer wet nappies or floppiness
Frequently asked questions
Can heat rash happen in winter?
Yes, if babies are overdressed or wrapped too warmly.
Is heat rash itchy?
It can be prickly or itchy, which may make your baby fussy.
Should I use powder?
No. Talc is not recommended for babies.
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Sources
- NHS: Heat rash (prickly heat)
- American Academy of Pediatrics, HealthyChildren.org: Heat Rash
- American Academy of Dermatology: Miliaria
This guide is general information, not medical advice. If you are worried about a rash, talk to your doctor.