Physical and Occupational Therapy

The Big Question: ICE or HEAT

Heat and Ice therapy are the most commonly used for joint, ligament, and muscle pain. Which one to use depends on a number of factors. The inflammatory process is a healthy, natural process that happens to be incredibly painful. Heat can make inflammation worse, and ice can make muscle tension and spasms worse, so they have the potential to do some mild harm when mixed up.


Cryotherapy is the use of ice to reduce the temperature of tissues to directly on or below the surface of the skin. Icing an injury can help reduce swelling and inflammation and causes vasoconstriction (the closing of blood vessels). Various cooling modalities are used to apply cold to the injured area which consist of  ice packs, ice towels, ice massage, frozen gel packs, and ice baths. The primary effects of cold packs include decreasing cell metabolism and with compression and elevation it limits the formation of edema. Cold packs decrease pain by slowing nerve conduction velocity and increasing the threshold of nerve endings [1].

How long should I leave cold packs on?

Treatment duration will depend upon the goal, target tissues, and the amount of adipose tissue. More adipose (fat) = longer duration. Applications should be no less than 2 hours apart.

The Injury Response Process

In acute injuries, the most beneficial effect of cold application is to reduce the need for oxygen. Compression tends to act better on deeper tissues. Activation of these cold receptors slowing nerve depolarization and re polarization decrease the transmission rate of impulses which in turn, decreases pain. When combined with an ice massage it triggers the large diameter nerves. Ice activates the gate control theory, inhibiting the transmission of pain [1].


Image result for moist heating pad in physical therapy

Moist heat packs should be at a temperature of about 160-166 degrees ferinheit. Heat causes vasodilation (the opening up of blood vessels) causing increased blood flow to the area. The main heat modalities utilized are moist heat packs, paraffin bath, and a whirl pool. The primary effects of heat include increased blood flow/ vasodialation, increased cell metabolism, decreased joint stiffness and increased soft tissue extensibility and flexibility.

Heat should be used for the followng: sub acute or chronic conditions, decreased ROM, hematomas, reduction of joint contractures, and infection.

How long should I leave moist heat packs on?

Duration varies and just like the cold therapy, when treating deep structures or a lot of adipose, treatment duration should be increased.

The Injury Response Process

Heat stimulates the skin thermo receptors that are connected to the blood vessels, causing the release of bradykinin which relaxes the smooth muscle walls resulting in vasodilation (increased blood flow) promoting healing.


To sum it all up,  a new injury will cause inflammation and possibly swelling. Ice will decrease the blood flow to the injury, thereby decreasing inflammation and swelling. Ice is most commonly used with sprains, strains, spasms, and arthritis. Pain that recurs and is chronic can be treated with heat, which will bring blood to the area and promote healing.

Questions and feedback are encouraged! If you are in need of Physical Therapy call Rehab Associates today at 740-345-2837 to schedule your appointment. 


  1. F.A. Davis, Starkey, Chad, April 6 2012. Therapeutic Modalities, Chapter 6

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