As the name implies, hot stone massage uses warm stones. The therapist places heated, smooth stones on specific points on the body and also holds the warm stones while giving the massage. The stones are usually basalt (a volcanic rock that retains heat well).
The warmth of the stones can be relaxing and can loosen tight muscles so that the therapist can reach areas of muscle tension quickly.
If you have certain medical conditions such as high blood pressure, diabetes, heart disease, or varicose veins, you should check with your health care provider if you plan on getting a hot stone massage. Likewise, if you take any blood-thinning medication, be sure to get a medical opinion first.