Skin Sensitivity to Heat and Sun

Heat can widen surface blood vessels and increase sweating, while sunlight can irritate or inflame exposed skin. Symptoms may be limited to sun-exposed areas or occur wherever the body becomes hot. The pattern can also be affected by medicines, skin conditions, dehydration, or heat intolerance. Heat exhaustion may cause heavy sweating, weakness, dizziness, nausea, headache, and cool or clammy skin, rather than being only a skin problem.

Move into shade or a cool indoor space, loosen tight clothing, and drink fluids if you can do so safely. Cover exposed skin with lightweight clothing, use shade, and choose a sunscreen that your skin tolerates. Keep a record of heat, sunlight, new products, medicines, and the timing of symptoms. Arrange a review if episodes keep returning or occur with palpitations, tremor, unusual sweating, weight change, or marked tiredness; hyperthyroidism can include heat intolerance.

Seek urgent help for confusion, fainting, severe weakness, inability to drink, trouble breathing, swelling of the face or throat, or a rapidly spreading blistering rash. Heat-related illness can worsen quickly. Get prompt advice for a painful rash, signs of infection, or symptoms that continue after cooling and leaving the sun.

Ask whether your symptoms fit heat intolerance, sun sensitivity, a medicine effect, or another skin problem. Ask which products and medicines may be contributing, whether blood tests are appropriate, and how to plan outdoor activity safely.