Heat and ice are the two most common types of passive, non-invasive, and non-addictive therapies. Heat and cold can be used alternatively and are often used as a prelude to exercise therapy.
Hot and cold agents should always be used with caution. It is a good idea to seek the advice of a healthcare professional prior to use.
Heat therapy induces vasodilatation: drawing blood into the target tissues. Increased blood flow delivers needed oxygen and nutrients, and removes cell wastes. The warmth decreases muscle spasm, relaxes tense muscles, relieves pain, and can increase range of motion.
Superficial heat is available in many forms, including hot and moist compresses, dry or moist heating pads, hydrotherapy, and commercial chemical/gel packs.
Hot packs in any form should always be wrapped in a towel to prevent burns. Punctured commercial hot packs should be immediately discarded, as the chemical agent/gel will burn skin.
Cold therapy produces vasoconstriction, which slows circulation reducing inflammation, muscle spasm, and pain.
Superficial cold is available in many forms, including a variety of commercial cold packs, ice cubes, iced towels/compresses, and forms of hydrotherapy. The duration of cold therapy is less than heat therapy; usually less than 15 minutes. The effect of cold is known to last longer than heat.
Cold or ice should never be applied directly to the skin. A barrier, such as a towel, should be placed between the cold agent and the skin's surface to prevent skin and nerve damage. Punctured commercial cold packs should be immediately discarded, as the chemical agent/gel will burn skin.