The question about when to use heat versus cold is often asked by my clients and patients. There are specific times when it is better to choose one over the other, and here are some specific instances. It is also good to consider each individual case and determine this based on a thorough evaluation performed by a physical therapist.
In general, ice is the preferred modality for decreasing inflammation or swelling. When there is swelling present, ice can help to decrease it and thus continue the healing process. Often, when someone has a high pain level or they have an acute injury then there is inflammation present, even if you can not see it from the outside. This is a great instance to use ice. The ice should go on the treatment area for 15-20 minutes, with a cloth or towel in between the skin and ice so it does not burn the skin. If an area is acutely inflamed, the heat can actually bring in more swelling to the area and make the problem worse.
Heat is good for bringing blood-flow to the area, such as when someone has a tight muscle or muscular spasm present. The increased blood-flow can allow for improved healing to take place as well as bring healing cells to the area to speed along the recovery process. The heat should be placed on the area of treatment for 15-20 minutes as well, and be sure to check the skin so that it reacts well to the heat. It should feel like a medium amount of heat, and not too hot thus could burn the skin.
Both heat and cold can serve a person well in order to decrease pain levels and muscle spasms. Some people prefer one modality versus the other in order to achieve this result, and the past results of heat or ice can be one aspect to consider as well. For example, if someone does not like the feeling of cold in general they may not respond well to using ice. If the ice causes someone to become cold and contract, and their problem was already that their muscles were too tight then this could make it worse. Conversely, as noted above, if the body part is acutely inflamed and someone uses heat instead of ice then this can make it more inflamed and worse.
There are also certain conditions or co-morbidities (a.k.a other issues in the body) that may preclude them to the use of ice or heat. People with Raynaud’s syndrome do not generally do well with ice due to the nature of their disease and that they already have cold hands and feet and impaired blood-flow. Also, some people with heart conditions do not do well with the use of heat because the heat can increase blood-flow and their heart rate too much. It is always a good idea to consult your physical therapist on the use of ice and heat, and they will help you determine what is best for you.