Infrared light (experienced as heat) is the invisible part of the sun’s spectrum with the ability to penetrate human tissue, giving a soothing, natural warmth. It is naturally occurring from the sun and is the basis for Sunlighten™ sauna therapy. Sunlighten’s Solocarbon infrared technology is therapeutic because it is 95-99% efficient at heating the body directly rather than simply heating the air. It works to raise the core body temperature to produce a deep, detoxifying sweat at the cellular level where the majority of toxins reside. How Safe is Infrared? Infrared heat is completely safe and healthy for all living things. You can be exposed to infrared light for hours without the risk of burning. Infrared is a naturally occurring output of the sun, but does not contain the harmful UV rays associated with unprotected sunlight. In fact, infrared heat is so safe, it is used in hospitals to warm newborn infants.