Stones (usually basalt) are placed into an electric slow-cooker or a purpose-built device which is filled with water. The water is typically heated to 122 – 127 degrees Fahrenheit (30-35 degrees Celsius).
Once the stones have heated sufficiently, some are placed onto specific points on the body such as the back, hands, etc… while others are held by the massage therapist and used to work the muscles.
Certain styles of stone massage also incorporate chilled stones into the routine. These stones are usually marble, and are placed into a bowl of iced water before use.