The main purpose of head cooling is to prevent the head from being burned, that is, to prevent changes in brain tissue caused by high fever, to prevent the emergence of cerebral edema, to reduce brain cell metabolism, to reduce the consumption of oxygen and energy, to improve the tolerance of brain cells to hypoxia, to prevent changes in brain disease caused by high fever, and to prevent damage to the central nervous system. Elevated body temperature is a test for human cells, and once it exceeds 42°C or 40°C, damage to cells is greatly present. In the clinic, the head can be cooled down individually by physical cooling, applying a low degree of white wine rub, or using an ice cap, which is a cap containing ice, and applying a wet towel, the purpose of these effects is to make the patient’s head temperature drop rapidly.