The correct application of heat compresses can reduce swelling. Hot compress for human soft tissue sprains, contusions and other pain and swelling caused by a very good elimination effect, generally 15-20 minutes each time. Hot compress is the use of hot towels, hot water bags and other auxiliary tools placed directly on the injured part, the use of thermal effects, to achieve the role of diastolic blood vessels, accelerate local blood circulation, but also to speed up metabolism, relieve muscle spasm, so that the absorption of blood stasis or tissue fluid. But one thing to note, should be in the 24-48 hours or so after the injury before the hot compress, if just injured on the hot compress will aggravate the local swelling. In addition, some unexplained abdominal pain and acute inflammation are not recommended to apply hot compresses, so as not to affect the judgment of the condition. When preparing a hot compress, pay attention to the temperature control, not too high, easy to burn the local skin; nor too low, the affected area can not achieve the therapeutic effect. If you use a hot water bag, it is recommended not to fill it too full, about 2/3 can, so as not to squeeze in the process, resulting in hot water bag rupture, scalding the skin.