A very popular but confusing question that arises nearly every day in my practice is, “Which is better for my condition, heat or cold?”

Much of this confusion can be alleviated with an understanding of the effects of each and of the healing process.

The effects of heat are threefold: it has a soothing effect on the nervous system, it relaxes the muscles, and it increases blood flow to the heated area. The last two effects go hand in hand since there is muscle in the covering of the arteries and if they relax, the artery expands (vasodilation).

As one might expect, cold produces opposite effects. It activates the nervous system, induces muscle contraction, and decreases blood flow to the cooled area through vasoconstriction.

So which is better depends on the type of injury and how recently it occurred.

In the initial stage of an injury (the first 24-72 hours), there is an inflammatory phase where the body allows an increase of blood flow to the injured area, which brings with it the necessary elements of healing.

This acute phase is characterized by pain, swelling, redness, heat and loss of function. During this phase, application of ice to the area to combat the swelling and heat as well as to provide an analgesic effect is recommended.

As healing progresses, the body moves into a proliferative phase where the elements of healing increase in number and the scar begins to take shape. This generally takes from as little as two days up to three weeks.

During this phase, much of the confusion takes place as cold is effective for pain relief, but heat can also soothe and since there is a decreasing amount of swelling, it can be used.

When in doubt, cold is the safer bet, but during this phase I recommend a combination of both, or a mix of the two. Three minutes of heat followed by 30 to 60 seconds of cold is very effective at reducing pain and swelling while allowing the wound to keep healing.

The final phase of healing is the remodeling phase, which lasts from three weeks to two years.

During this phase, the scar tissue gets strengthened. There are very few physical indications that there is a problem anymore as swelling and pain are almost absent.

During this phase, heat soothes what pain may be present and allows the scar tissue to remain flexible.

If, however, the area is injured again, the inflammatory phase begins anew and it’s time to return to ice to start the whole process again.