Heat and cold are both effective home remedies for sore back muscles, but they need to be used in the correct order to help relieve pain and stiffness. If you don't know what caused your back pain or you also have any numbness, tingling, shooting pains or fever, be sure to speak to your health-care provider.
Cold compresses decrease blood circulation to the painful area, which reduces inflammation and swelling at the site. Cold temperatures also slow the transmission of pain signals that are sent to your brain, according to the "American Medical Association Handbook of First Aid and Emergency Care." Apply the compress for no longer than 20 minutes, but use them up to 8 times a day for the first 2 to 3 days after developing a sore back muscle.
Switch to heat after 24 hours of cold therapy to restore blood flow and relax your muscles. According to back pain treatment guidelines published by the American College of Physicians and the American Pain Society, heat can be applied in the form of heating pads or warm blankets for up to 20 minutes. Be careful not to sleep with a heating pad, which can cause accidental burns.