While many understand that heat and cold therapy can be useful for pain, there can still be questions. How long should you leave the heat or ice on? Should you use heat or cold for the type of pain you are experiencing?

According to Waldman’s (2007) Pain Management, Volume II, heat therapy causes:

  1. An increase to the flow of blood in the area to which heat is applied.
  2. A decrease in the stiffness of the joint.
  3. A decrease in any possible swelling caused by fluid build-up.
  4. A reduction of pain.
  5. Restoration of movement to the painful area.

Heat therapy should be used in instances where the muscle is spasming or sore. Heat therapy, by nature, causes vasodilation which is the process by which the above five reactions occur. If the pain that is being experienced is in any way constrictive (stiff, immobile joints, muscle spasms, tight muscles, sore muscles), then it’s safe to assume that heat therapy would be the best for that type of pain.

There are many forms of heat therapy that can be purchased – chemical heat packs that activate when shaken, hot tubs, and microwavable heat packs are all easy to obtain. Heat therapy can be applied for a span of time from 30 minutes to 2 hours, depending on the method of heat.

Specific pain that can be treated with heat therapy include fibromyalgia pain, arthritis pain, and sports related pain.

Cold therapy should be used for injuries or pain that are swollen and/or inflamed in nature. Sprains due to injury can be treated with cold therapy, as well as inflamed joints due to arthritis.  According to Waldman’s (2007) Pain Management, Volume II, cold therapy causes vasoconstriction, which slows circulation, aiding in reduction of swelling and inflammation. If the area of pain is swollen and/or inflamed, it is safe to assume that cold therapy is the preferable treatment.

Waldman (2007) states that something as simple as a bag of frozen peas can be used as a cheap and easy form of cold therapy. Other forms of cold therapy can be commercially available cold packs, ice and cold water in a sealable plastic bag, or an ice bath. Always place a layer of fabric between the cold source and skin, and only use cold therapy for 15 minutes.


Waldman, S.D. (2007) Pain Management, Volume II 1033-1042 Philadelphia: Saunders Elsevier