Hot or cold applications are used to treat almost every disease affecting the musculoskeletal system, from rheumatic joint pain to muscle strains and herniated discs. Hot and cold applications can be performed in physical therapy units, but most of the time they can also be performed at home on their own. As a general rule, cold application is used for the treatment of sudden (acute) injuries and pain. In acute injuries, inflammation (immune system activation) and edema are high. Cold application reduces this. Hot application is generally preferred for long-standing (chronic) problems. Hot treatments reduce muscle pain and spasm. Sometimes both hot and cold applications can be used alternately in the same person or for different body parts at the same time.
Working Mechanism of the Hot Application
With hot treatment, the vessels dilate (vasodilatation). Thus, more oxygen and nutrients reach the tissue. Waste materials are removed faster with increased circulation. Transmission of heat sensation signals by nerve fibers reduces the pain sensation signals reaching the brain. Hot treatment is useful in reducing connective tissue stiffness and dissolving tissue adhesions. With warming up, muscle spasm is resolved, pain is relieved and joint range of motion is increased.
Working Mechanism of Cold Application
With cold application, constriction of the vessels (vasoconstriction) is provided. Thus, blood flow in a certain area can be reduced. Accordingly, immune system activity (inflammation) and edema decrease. Since edema in joints and tendons causes pain, reducing edema relieves pain. In addition, the temporary decrease in the activity of nerve fibers with cold application also contributes to the reduction of pain.