Heat rash, also known as prickly heat and corn rash, can be categorized as white heat, red heat, pus heat and deep heat, with different symptoms, including superficial blisters and other common symptoms. 1. White prickly heat: often manifested as superficial blisters, the size of a needle tip, no redness around, easy to break. There are often no conscious symptoms. 2. Red prickly heat: often manifested as pinpoint-sized papules, papules, which are often arranged densely. It is often surrounded by a red halo, and may be mildly flaky after the lesions subside, accompanied by burning and itching sensation. 3. Pustular heat rash: mostly developed from red heat rash. It is characterized by dense papules with pinpoint-sized potential pustules at the top of the papules. 4. Deep prickly heat: It is often manifested as dense non-inflammatory papules consistent with sweat pores. The lesions are inconspicuous when not sweating and increase in size when sweating. There are usually no conscious symptoms, but systemic symptoms, such as headache and fever, can occur when the lesions are widespread. If there is any discomfort, it is recommended to seek prompt medical attention for diagnosis and treatment.