What should you know about a flat heat rash?

Heat rash, also called prickly heat or miliaria, develops when sweat ducts become blocked and sweat irritates nearby skin. It may look like a flat red, pink, or darker patch, sometimes with tiny bumps or a prickling itch. Common areas include skin folds, the neck, chest, back, and places covered by tight clothing. The condition itself is not the same as a heat emergency, but symptoms can overlap with other rashes.

A rash that continues outside hot or humid conditions may have another explanation, such as contact irritation, eczema, or infection.

Move to a cooler place, rinse with lukewarm or cool water, pat dry, and wear loose breathable clothing. Keep sweaty skin dry and avoid thick oils, fragranced products, and heavy occlusive creams over the affected area. A simple emollient may help if the skin is dry or rubbing. A clinician may recommend a short course of topical corticosteroid for marked inflammation; use it only as directed.

Arrange medical advice if the rash is spreading, very painful, blistering, draining, or not settling after the heat and sweating stop. Seek urgent care for fever, confusion, faintness, severe weakness, or signs of a serious heat illness. Children, older adults, and people who cannot regulate body temperature need particular caution.

Ask whether the pattern fits heat rash, whether another rash should be excluded, and which product is suitable for your skin. If a steroid is suggested, ask where to apply it and when to stop.