... When the jade is heated, it emits infrared rays that penetrate the body 14-15cm ... inches). When the jade is heated, it emits infrared rays thatpenetrate the body 14-15cm (5.5 ... loess). When the jade is heated, it emits infrared rays that penetrate the body 14-15cm (5.5 ... good radiators of infrared radiation, when gently heated by the elements in the mattress. DKY electric far-infrared jade heater