Heat or cold therapy works by stimulating your body’s own healing force. For instance, heat dilates the blood vessels, stimulates blood circulation, and reduces muscle spasms. In addition, heat alters the sensation of pain. You can use either dry heat — such as heating pads or heat lamps — or moist heat — such as warm baths or heated wash cloths.
Conversely, cold compresses reduce swelling by constricting blood vessels. While cold packs may be uncomfortable at first, they can numb deep pain.
When using moist heat therapy, make sure the temperature is not so hot that you burn your skin. Find a temperature that you can comfortably tolerate, whether using a bath, hot water bottle, or spa therapy.
You also need to give it time to work. Use the moist heat application for at least 15 minutes before exercise. Then use it again immediately following exercise. You can also use moist heat anytime you want additional relief from arthritis pain.