Heat rash refers to prickly heat. Common symptoms include small blisters and pimples, which may also be accompanied by itching and tingling of the skin. Prickly heat is caused by the fact that sweat cannot be discharged normally in a hot and stuffy environment. It is classified as white prickly heat, pus prickly heat, red prickly heat and deep prickly heat, with some differences in symptoms. The common symptom of white prickly heat is superficial blisters of pinpoint size on the local skin, but without redness around them, easy to break, and generally without self-conscious symptoms. Pustular prickly heat lesions are dense papules with pinpoint-sized superficial pustules at the top. Patients with red prickly heat show a dense arrangement of pinpoint-sized papules, papules, but surrounded by a red halo, the lesions subside after a mild flaking, but also accompanied by burning, itching sensation and other uncomfortable symptoms. As for prickly heat, the lesions are characterized by dense non-inflammatory papules, and the lesions increase in size when sweating; there is usually no itching, but systemic symptoms such as headache, fever and dizziness may occur when the lesions are generalized. Usually, prickly heat can be cured by itself without special treatment, but for those with serious conditions, it is recommended to follow the doctor’s instructions to use medication, not indiscriminate use of drugs. Pay attention to daily skin care and keep the skin area fresh and dry.