Sprain to the foot for hot or cold compresses, need to be carried out according to the specific time period. In the sprain should be taken when the cold compress, cold compress about 5 minutes can be effective to let the blood vessels constriction. Because after the injury blood vessels will have ruptured blood seepage, through cold compresses after vasoconstriction can reduce the amount of local bleeding, which can effectively prevent bruising swelling and inflammatory edema aggravation, to avoid slow recovery. About 48 hours after the sprain, when the ruptured blood vessels have closed and there is no more bleeding, hot compresses can effectively increase vasodilation, increase local blood circulation, increase venous reflux, which can promote the metabolism and absorption of bruising and swelling and inflammatory edema; and arteries will also be expanded, local energy, nutrition, electrolytes and other components can get more support, which can Promote the healing of the sprained area.