Heat therapy, also known as thermotherapy, involves the application of heat to specific areas of the body. This treatment can be delivered in various forms, including heat pads, hot water bottles, or warm towels. The primary mechanism by which heat pads relieve pain is through vasodilation—the widening of blood vessels. When heat is applied to the skin, it increases blood flow to the affected area, delivering essential nutrients and oxygen needed for healing while removing metabolic waste.