What should you know about hives with temperature?

Hives are raised, itchy welts caused by the release of inflammatory chemicals in the skin. Heat, exercise, hot showers, cold air, cold water, or a rapid change in temperature can provoke some people. A fever may occur alongside hives when an infection or another illness is present, but the fever itself does not identify the cause. Individual welts often fade and reappear elsewhere; swelling around the lips or eyes can occur with hives and is called angioedema.

Notice what happened before the eruption: sweating, a chilled environment, a new medicine, food, pressure, or an illness. A photograph and a brief symptom diary can help a clinician separate temperature-triggered hives from another skin rash.

Move to a comfortable, steady temperature and avoid very hot showers, vigorous overheating, and direct cold exposure while symptoms are active. Wear loose clothing, use a cool—not icy—compress, and try not to scratch. A clinician or pharmacist can advise whether an oral antihistamine is suitable, especially if you take other medicines or have a health condition. Do not stop a prescribed medicine without discussing the timing and reaction with its prescriber.

Seek emergency help for trouble breathing, wheezing, faintness, confusion, or swelling of the tongue or throat. Get prompt medical assessment for hives with repeated vomiting, severe weakness, a rapidly worsening fever, painful skin, blistering, or purple marks. Arrange a routine review if episodes keep returning, last beyond a brief episode, disturb sleep, or need frequent treatment.

Could heat, cold, sweating, infection, or a medicine be triggering my hives? Which treatment is appropriate for my symptoms, and what should I do if facial swelling appears?