Heat and cold are the two most common types of noninvasive and non-addictive pain-relief therapies for muscle and joint pain. Which one you use depends on whether the pain is new or recurring. Alternating Hot & Cold Therapy is great for all types of pain relief. Heat Therapy provides pain relief by relaxing the muscles, increasing circulation, stimulating blood flow, reducing stiffness, and increasing your range of motion. Cold Therapy provides pain relief by numbing the area affected by pain and reducing inflammation.