How long can you apply hot compresses after playing closed needle, due to different personal constitution so there are differences in time, can not be generalized, generally need about three days. The closed needle is closed treatment, closed therapy is a different dose of different concentrations of local anesthetic drugs, injected into the local tissue to relieve pain. Just after the closed injection there will be a needle eye survival, at this time can not be hot compresses, if the needle eye before the disappearance of hot compresses, may lead to infection of the needle eye, is not conducive to recovery. After the closed injection, you need to pay attention to the protection of the injection site, to avoid the eye of the needle touching water, etc., it is recommended to use Band-Aid to bandage the eye of the needle, and so the eye of the needle disappeared, and then hot compresses. If you feel uncomfortable after playing closed injection, you should go to the hospital in time to avoid delaying the condition.