Generally after the injury in 12 hours or less hot compresses, some can be considered in 24 hours, or even 48 hours later, try to avoid in the trauma of the acute inflammatory period of hot compresses. In the acute inflammatory period, local tissue edema, vascular expansion, hot compresses will lead to more obvious vascular expansion, fluid aggregation is more obvious, resulting in swelling and pain is more powerful, so in the local inflammation to be slightly relieved hot compresses, the expansion of blood vessels at this time in turn can promote blood flow, reduce swelling. It should be noted that, if the hand wound has obvious skin breakage or bleeding, hot compresses are not appropriate, on the one hand, it will lead to pain, on the other hand, it is very likely that the hot compresses with other moisture or unclean substances, which will lead to local infections and so on.