Medicare Instant Hot Pack for Powerful Heat Therapy. Relax and loosen sore, tired and stiff muscles with the Medicare Instant Hot Pack. This Hot Pack provides form-fitting, flexible hot therapeutic relief for arthritis, muscle spasms, menstrual cramps and more. Hot Therapy can also be used before or after exercise to improve mobility by loosening muscles and increasing joint elasticity. Heat packs are particularly popular among people who experience lower back pain. Hot therapy can also be used to increase the range of motion. This pack heats to an ideal temperate to apply healing and calming heat to an injury, without burning a patient’s skin or making them feel uncomfortably hot. This pack is both portable and convenient to use in any number of locations and, as such, it is ideal for paramedics, first aid personnel and sports coaches, as well as picnickers.