Itching in winter when exposed to heat may be caused by dry skin syndrome, cholinergic urticaria, eczema and other reasons. 1. Dry skin syndrome: due to the winter temperature is relatively low, the air is relatively dry, the body sebaceous glands and sweat glands of the secretion of the obvious reduction, easy to lead to the skin is particularly easy to dry, triggered by dry skin, dry skin is easy to cause itching after the heat. 2. Cholinergic urticaria: cholinergic urticaria is a type of urticaria, is due to the peripheral nerve release of acetylcholine caused by the skin disease, which is more in the movement, nervousness, emotional fluctuations, drinking hot food after the onset of the wind, accompanied by itching symptoms, the patient appeared in the winter when the body is hot on the itchy case, it may be caused by cholinergic urticaria. 3. Eczema: Eczema is a kind of inflammatory skin disease caused by a variety of internal and external factors with intense itching, mostly occurring in the fall and winter seasons, and itching in winter when the body is hot may be caused by eczema. It is recommended that patients seek medical examination in a timely manner, clear causes for targeted treatment, pay attention to personal hygiene in life, maintain a good emotional state, avoid scratching the affected areas.