So: infrared is not heat, nor does it (directly) cause heat; it's emitted by the heat of object at a certain range of temperatures. 3.3k Views ยท View Upvoters Cyril Anderson, Physics grad, 2000. read more
Far Infrared is the heat energy emitted from the sun and can heat objects without any medium. The Far Infrared heat therapy in the Amethyst crystal mats generate the same rays using natural crystals. FIR Rays are invisible waves of energy that has the ability to penetrate all layers of the human body into the innermost regions of the cells, tissues, muscles and bone. read more
Because most heat generates light in the infrared, scientists often refer to infrared light as heat. This is a generalized term or a convention. Technically heat energy and light are different things, but heat energy can be measured by its EM radiation. read more