The Medicare Cold Hot Pack Reusable combines the benefits of both hot and cold therapy for effective pain relief and recovery. It's recommended by experts for treating sprains, strains, bruises, and swelling, as well as headaches and minor injuries. After the initial 3 to 5 days of cold therapy for an acute injury, experts suggest alternating between hot and cold therapy for optimal pain relief and recovery from muscle tears, overuse injuries, and chronic joint pain. The pack's reusable design makes it easy to use: simply pop it in the freezer for cold therapy or the microwave for hot therapy.