A hot stone massage involves the therapist using smooth, flat, and heated rocks placed at key points on the body. The stones (usually basalt) are first heated to 122–127 degrees Fahrenheit. Some stones may then be placed onto specific points on the body (such as the neck, back, hands, etc.), and others may be held by the massage therapist and used to work the muscles. The heated stones help concentrate heat and improve blood flow to certain points on the body which may require additional attention in order to relieve pain, stiffness, or improve range of motion.