The use of non-pharmacological means to lower the temperature is called physical hypothermia, physical hypothermia has a rapid onset of action, small adverse effects, simple and safe, is one of the better ways to lower the temperature, all age ranges can choose to fit their own conditions of physical hypothermia to assist in reducing fever. However, despite the wide scope of application of physical cooling in the clinic, there are still contraindications and precautions for different groups of people in the selection of physical cooling methods, as follows: First, whole-body cold therapy, including warm-water baths and alcohol baths, is suitable for patients with hyperthermia physical cooling methods. Among them, warm water bath is suitable for patients of any age, while alcohol bath can be used by other age groups except for newborns and patients with hematologic hyperthermia. The method is to dip the towel into warm water or ethanol, wring to half dry, centrifugal direction of swabbing, wipe to the armpits, groin and other parts of the blood vessels, wipe time can be a little longer, in order to help dissipate heat. Wiping process should also closely observe the patient with or without chills, pallor, pulse and respiratory abnormalities, if there is anomaly, it should be stopped in a timely manner swabbing, timely treatment. Second, local cold therapy local cold compresses suitable for patients of any age, usually used when the body temperature is below 39 ℃. Local cold compresses often use ice packs, antipyretic patches and cold towels placed on the forehead, the top of the head, the sides of the neck, armpits, groin and other places, and the time should not exceed 30 minutes. Local cold compresses should be observed during the process of the patient’s local skin, if there is purple, numbness, then it should be stopped immediately.