Far Infrared rays have the ability to penetrate, refract, radiate and reflect. The human body can absorb FIR because of its deep penetrating ability. When FIR penetrates through the skin to the subcutaneous tissues, it transforms from light energy into heat energy. The thermal effect within the deep layers of the tissues causes blood vessels and capillaries to dilate, promoting better blood circulation, and the heat helps get rid of body toxins and metabolic wastes through sweating.