Heat therapy is grounded in the principle of thermoregulation. When heat is applied to a painful area, it causes blood vessels to dilate, enhancing circulation. This increase in blood flow can help clear out inflammation and bring in healing nutrients to the muscle or joint in distress. Additionally, the warmth can stimulate sensory receptors in the skin that help to reduce the perception of pain, making it an effective tool for those suffering from chronic conditions such as arthritis or lower back pain.