What should you know about heat rash in a newborn?

A newborn may develop tiny pink, red, or clear spots in areas that become warm and damp, such as the neck, chest, back, or skin folds. The rash may feel prickly, and some babies become unsettled when clothing or a fold touches it. Heat rash, also called miliaria or prickly heat, happens when sweat cannot escape easily from the skin. Its appearance can vary with skin tone, so changes in texture, warmth, and behaviour matter as well as colour.

Move the baby to a cooler, well-ventilated room and remove an extra layer. Dress them in loose, breathable clothing and change damp garments or bedding. Bathe with lukewarm water, pat the skin dry, and give folds time to air-dry. Avoid heavy oils, thick ointments, fragranced products, and powders that may trap moisture or irritate delicate skin. Do not scratch or scrub the area. If dryness remains after cooling, ask a clinician whether an appropriate emollient is suitable; see [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/).

Seek prompt medical advice if the baby has a fever, seems unusually sleepy, feeds poorly, breathes differently, or has fewer wet nappies. Arrange an assessment if the rash blisters, oozes, becomes painful, spreads quickly, or does not start settling after cooling. A clinician can distinguish heat rash from infection, eczema, or another [Skin Rash](/symptoms/skin-rash/). Do not apply a steroid cream to a newborn unless it has been specifically recommended for that baby.

Ask whether the location and appearance fit heat rash, which products should be stopped, and how to keep the folds dry during feeding and sleep. Mention any fever, change in feeding, new detergent, or recent change in clothing. If treatment is discussed, ask whether [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) are appropriate for the baby’s age and body area.