Cold packs are a frozen gel substance used by physical therapists to treat areas of pain and inflammation. The cold packs are wrapped in wet towel and applied directly to the area in need of treatment. The cold transferred to the patients skin, muscle, and tissue has several beneficial effects. The cold temperature causes vasoconstriction of the blood vessels in the area. This decreases the inflammation in the area. By decreasing inflammation, pain and swelling are decreased. This in turn decreases pain. Management with ice is the first line of treatment in acute injury.