... , soreness and stiffness. Designed for treating larger areas such as the legs, upper back, or abdominal area. The ... away the wastes, which may hinder healing. Sufferers of back pain, arthritis, muscle aches, tendonitis, and tension, ... the moist heat pack back for 1 minute, if more heat is needed, heat for 10 seconds at an interval ... cold: put the moist heat pack back in freezer for at least 2 hours.