Benefits Of Heat Therapy

It is a well documented fact that heat relieves pain.

Historically, heat has been a natural remedy used both to relieve pain and enhance the recovery process. By increasing the temperature of the skin surface and underlying tissues, heat stimulates the thermo receptors- sensory receptors that respond to heat and cold - which then help block transmissions of pain signals to the brain. This translates into a significant decrease of discomfort.

Heat therapy increases blood flow, which helps to decrease stiffness, relaxes sore muscles, and provides soothing comfort.

Heat should not be used on areas of swelling and bruising. (If swelling occurs, use ice, then apply heat after the swelling goes away.)

What is happening here is strange but can be understood if you think about water freezing. Water freezes at 32 degrees F or 0 degrees C. If you were to stick a thermometer in a cup of water and put the cup in the freezer, you would find that the temperature of the water falls to 32 degrees F and then hangs there until all of the water is completely frozen. Then the temperature of the solid water falls to the temperature of the freezer.

 What if you could somehow supercool the water? That is, say that you could get the water's temperature to 10 degrees below freezing without it crystallizing into a solid (you can sometimes do this using a very clean glass and distilled water so there are no points for the water to begin crystallizing). In this condition you can tap the glass and the temperature of the water will jump up to 32 degrees F/0 degrees C and the water will solidify quickly.

Our magic heating pads contain sodium acetate and water. It turns out that sodium acetate is very good at supercooling. It "freezes" at 130 degrees F or 54 degrees C, but it is happy to exist as a liquid at a much lower temperature and is extremely stable. Clicking the disk, however, has the ability to force a few molecules to flip to the solid state, and the rest of the liquid then rushes to solidify as well. The temperature of the solidifying liquid jumps up to 130 degrees F or 54 degrees C in the process.