What should you know about red spots due to heat?

Hot, humid conditions increase sweating. Sweat, occlusive clothing, and rubbing can irritate the openings of follicles and create small red or prickly bumps. Heat can also make rosacea-related flushing more noticeable. Folliculitis may resemble a heat rash when bumps are centred on hairs, while acne can flare when sweat and products remain on the skin. The appearance alone cannot confirm which process is present.

Consider where the spots occur, whether they sting or itch, and whether they fade after cooling and washing. A new sunscreen, cosmetic, or fabric may cause contact irritation rather than a heat response.

Move to a cooler setting, rinse off sweat with lukewarm water, and pat rather than rub. Wear loose, breathable clothing and change damp garments promptly. Keep skincare light and fragrance-free while the rash is active; avoid thick occlusive products and scratching. Do not squeeze bumps. If the pattern returns with exercise or warmth, record the trigger and affected areas for a clinician.

Seek medical advice if the spots persist after cooling, recur frequently, become painful or pus-filled, or spread. Get urgent help for breathing difficulty, facial swelling, faintness, fever, confusion, or rapidly worsening skin changes.

Ask whether the eruption is heat rash, folliculitis, acne, rosacea, or contact irritation, which products are suitable in hot weather, and how to prevent flares during exercise or outdoor time.