Itching of the scalp when it is hot may be due to a certain inflammatory irritation of the scalp area, mostly due to seborrheic dermatitis of the scalp. There are many clinical causes for this condition, for example, it may be triggered by bad habits. In particular, some people may often stay up late, overworked or often eat spicy and stimulating foods, which may cause a certain seborrhea, and the overflowing cortex may lead to secondary infection of the scalp by Malassezia, resulting in the formation of certain flushed patches. If heat is applied at this time, it may cause capillary dilation and release of inflammatory mediators, which will inevitably produce itching.