There is still controversy over this question and I often hear what I believe to be incorrect information given out by medical professionals. The guidelines for hot and cold applications found in Chaitow and Delany’s Clinical Applications of Neuromuscular Techniques makes the most sense to me.

This is the general guideline for muscles that I give patients in my Neuromuscular Therapy center near Boston:

Use ice for pain and spasm. Use heat for achiness and stiffness.

To promote healing in soft tissue, create change. Short applications of either heat or ice get the attention of your body’s balancing systems and force them to change the activity in the tissue to restore balance.

Ice pack use: To prevent an ice “burn” do not use ice or an ice pack directly on the skin. Use a thin cloth such as a dishcloth or pillowcase to protect your skin from injury.

Leave an ice pack on for one to five minutes. One minute is enough to increase blood flow and flush waste products. Long applications of ice decrease the flow of fluids and harden connective tissue, but help to decrease pain and muscle spasm by dulling the nerves. Warm your skin after icing for longer time periods to restore blood flow.

Hot pack use: Moist heat is best and should never be hot enough to scald the skin.

Leave a hot pack on for one to five minutes. One minute is enough to dilate the blood vessels and increase blood flow. Long applications of heat decrease blood flow by creating congestion and swelling.

Contrast therapy, alternating short applications of ice and heat, improves drainage and brings nutrients and oxygen to the tissues.