Heat rash on the skin: what to know

Heat rash can develop where sweat is held against the skin by humidity, exercise, bedding, close clothing or skin folds. It may feel prickly or itchy and appear as small clear, flesh-coloured or red bumps. Some people notice mild redness or a stinging sensation. The appearance may vary with skin tone and body site. A general heat link supports the possibility, but the same symptoms can occur with eczema, contact irritation, bites or infection, so the pattern and progression matter.

Learn more on [Heat Rash](/conditions/heat-rash/). The symptom pages for [Skin Rash](/symptoms/skin-rash/), [Skin Bumps](/symptoms/skin-bumps/) and [Skin Redness](/symptoms/skin-redness/) may help you describe what you see.

Move to a cooler place, loosen or remove damp clothing, and use a cool shower or damp cloth. Pat the skin dry and choose breathable fabrics. Avoid scratching, thick greasy products, fragranced cosmetics and further heat over the area. If dryness remains after the rash settles, ask a pharmacist or clinician about [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/). Do not start a medicated cream simply because a rash looks similar to a previous one; [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) should be selected and used according to clinical advice.

Book an assessment if the rash is painful, hot, swollen, blistered, crusted, oozing, recurrent or not improving after the skin is cooled and kept dry. Fever, marked illness, rapidly spreading redness or a rash involving the eyes or mouth needs prompt attention. Call emergency services for breathing difficulty, facial or tongue swelling, faintness or a sudden widespread allergic-looking eruption.

What features make this heat rash rather than eczema, contact irritation or infection? Which products should I stop? How can I protect the area during exercise or hot weather? Is a moisturiser or medicated cream appropriate? What changes mean I should seek urgent assessment?