What causes some people to develop prickly heat?

Some people may develop heat rash, and the main contributing factors include: 1. Environmental factors: Prolonged exposure to high temperature and humid environments increases perspiration while reducing evaporation, leading to blocked sweat ducts and leakage of sweat into surrounding tissues, thus causing heat rash. Heat rash is more likely to occur in summer when temperatures are high and humidity is elevated. 2. Skin characteristics: Infants' and children's skin is thinner and more delicate, and their sweat glands are not fully developed, making them more susceptible to irritation from sweat, which may lead to heat rash. 3. Clothing and lifestyle habits: Wearing non-breathable or tight-fitting clothing, long-term bed rest, or being in a weakened physical condition may all impair the skin's normal heat dissipation and perspiration, increasing the risk of developing heat rash. 4. Other factors: Prolonged sun exposure, excessive internal dampness and heat, and a lack of vitamin D may also contribute to the occurrence of heat rash. Additionally, individuals with allergic constitutions may develop heat rash upon contact with allergenic substances.