Heat

NEVER use heat on a new injury.  So when is heat appropriate?  Generally speaking, heat is best utilized once the swelling, bleeding and inflammation processes have ceased and mobilization has begun.  Often, even at this stage, ice remains the better choice and heat is best used only with chronic arthritic conditions or as preparation for a stretching program.

Using heat may aggravate a condition.  If you use heat when dealing with the early stages of an injury, or with an injury that's repeatedly aggravated, the heat will aggravate the damaged tissue and increase the symptoms rather than alleviate them.  If in doubt, it's always better to use ice.

Whether heat is applied in moist hot packs, heating pads or whirlpool baths, the suggested temperature is between 102F and 110F.  Benefits of properly applied heat include an increase in metabolic rate and nutrition, tissue plasticity and oxygen perfusion, as well as a decrease in muscle spasm.  

Those with circulatory disorders, fragile skin or impaired sensation should not use heat.  As with ice, do not use on the front of the neck over the carotid arteries as heartbeat and breathing may be affected.