Heat rash welts: what the bumps may mean

The bumps may be skin-coloured, pink, or red and can feel prickly or itchy. They often cluster where sweat collects, such as the neck, chest, back, folds, or beneath clothing. Heat rash is covered in the [Heat Rash](/conditions/heat-rash/) guide. Because hives, bites, folliculitis, and contact reactions can also form raised areas, the appearance alone cannot confirm the cause. Compare symptoms with [Skin Bumps](/symptoms/skin-bumps/) and [Skin Rash](/symptoms/skin-rash/).

Cool the body, loosen clothing, and let air reach the affected skin. Wash gently without scrubbing, then pat dry. Use a cool damp cloth for short periods and avoid heat, fragranced products, thick occlusive ointments, and scratching. If the skin is dry rather than sweaty, discuss [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/) with a clinician. Do not start a steroid cream on a widespread or uncertain rash without advice.

Seek medical advice if welts are painful, blistered, pus-filled, persist despite cooling, or recur without an obvious heat trigger. Get urgent help for swelling of the lips or tongue, breathing difficulty, faintness, or a rapidly spreading rash. A clinician may distinguish heat rash from hives or infection and decide whether [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) are appropriate.

Ask what features separate heat rash from hives, whether a medicine or product could be involved, and how long to try cooling measures before review.