Heat rash in winter: what to know

Several layers, heated rooms and non-breathable fabrics can create a warm, damp microclimate next to the skin. Sweat may collect under collars, waistbands, socks or blankets, leading to prickling, small bumps and redness. Dry winter air can also irritate skin, so a [Skin Rash](/symptoms/skin-rash/) is not automatically heat rash. The location, timing after sweating and response to cooling help guide an assessment.

Remove or loosen a layer when you begin sweating and change damp clothing. Prefer breathable fabrics, ventilate overheated rooms and avoid tightly wrapped blankets over an active rash. Wash gently with lukewarm water, pat dry and use a cool cloth for prickling. If cold air and washing leave surrounding skin dry, a bland [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/) product can support the skin barrier. Ask before using [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/), particularly on folds or delicate areas.

A clinician should review a rash that persists after layers and sweating are addressed, repeatedly returns, or looks different from prior episodes. Seek prompt care for increasing pain, pus, fever, extensive swelling, blisters, open skin or rapid spread. New [Skin Bumps](/symptoms/skin-bumps/) that are firm, very tender or draining may need a different diagnosis and treatment.

Ask whether winter layering, indoor heating, dry skin or another condition best explains the change. Discuss suitable fabrics and moisturisers, whether a product should be stopped, and which warning signs require a faster appointment.