Physical therapists wrap moist hot packs in several layers of towels. They are then applied directly on the exposed area that needs treatment. The heat provided by the hot packs has several important benefits. It relaxes tight muscles causing tissues to relax. This decreases pain caused by muscle tension or spasms. It also causes vasodilatation of the blood vessels which increases circulation to the area. Patients with muscle strains, spasms, or arthritis often benefit from treatment with moist hot packs.