Ice or heat -- also called hydrotherapy -- can be wonderful self-care tools for muscle strains, sprains, and other injuries. When used properly, they are safe, effective, and free. What's not to like about that?

But there often seems to be confusion about which to use when. Below is a handy guideline.

But in general, here's a memory aid:

(Heat will make inflammation worse, increasing pain and swelling in a recent injury. Don't do it!)

You can learn more specifics about using ice here.

Learn to perform ice massage--one of the best things you can do for tendonitis--here.

And you can learn more details about using heat effectively here.

And you can learn a powerful hot-and cold technique called contrast therapy here.

*With regard to "recent" injuries, it's not so much the time elapsed as the state of the injury. If it's still inflamed, red, warm to the touch, or hurts to the touch--you should not apply heat yet.

Learn more specifics about using ice here.

Learn more details about using heat effectively here.

And learn a powerful hot-and cold technique technique called contrast therapy here.