The main cause of prickly heat is due to poor sweat drainage and blockage of sweat ducts, which is related to the development of sweat ducts, climatic factors, physical activities and other factors. 1. Sweat duct development: For newborns, sweat ducts may not be fully developed yet, which makes them prone to prickly heat. 2. Climatic factors: People who are active in humid and hot environments are more prone to prickly heat because they sweat too much, which does not evaporate easily, leading to poor sweat drainage and blockage of sweat ducts. 3. Physical activity: For people who engage in strenuous exercise or work outdoors in high temperatures, they may sweat more, thus increasing the risk of prickly heat. There may be other reasons for prickly heat, such as febrile illness, ultraviolet radiation and electricity radiation, etc. Therefore, you should cooperate with your doctor to clarify the specific causes before treatment, and don’t blindly use medication.