How do FIR sauna heaters work?

An infrared sauna heater works through infrared light. Infrared light is completely different from UV light which can lead to skin cancer. Although neither type of light is visible to the human eye, ultraviolet light has a shorter wavelength than visible light, while infrared light has a longer wavelength.

Infrared light is also commonly known as infrared radiation, and in itself it is a type of radiant heat. FIR saunas work by emitting infrared radiation from heating panels which is then absorbed directly by the human body. The body is heated directly, so no heat is lost in heating the air. Air temperatures are typically around 40-60°C in an FIR sauna, as opposed to the standard sauna temperature of 60-90°C.