Far-Infrared saunas are often called soft saunas because they produce higher humidity at lower temperatures. Some argue that these saunas are not “true” to the sauna tradition. Far-Infrared Rays are the invisible portion of the light spectrum emitted by the sun. Far-Infrared Rays carry heat deep into the skin and muscle tissue without high surface temperatures. Far-Infrared Rays heat the body directly which raises the core temperature and produces a deep penetrating, detoxifying sweat at the cellular level. It takes approximately 10 minutes to heat up a Far-Infrared Sauna.