Ice is generally prescribed in the acute stages of healing, the period occurring right after the onset of pain or injury and lasting up to three days. The cold temperature makes the blood vessels in the sore area vasoconstrict (become narrower), assisting with the initial stages of healing. Putting cold on the sore muscle is known to ease pain, but it doesn’t always take away swelling. If the temperature is too cold, the body may be triggered to actually pump extra blood to the sore spot, making the swelling worse. To prevent this, layer a towel over your skin before applying the cold treatment. In general, cold treatments can include cold packs or ice bags, which are generally put on the sore muscle for 10 to 15 minutes.