Red light therapy, also referred to as photobiomodulation, is a method that uses light of specific wavelengths to positively affect cellular functions. For this purpose, panels with LEDs that emit red light and near-infrared light are used. These specific wavelengths of light have the ability to penetrate the skin into deeper tissues. Unlike conventional heat sources such as infrared radiators in a sauna, this therapy does not primarily heat the body. Instead, the light energy is absorbed by cellular structures called mitochondria, which act as "cellular power plants." This process stimulates the mitochondria to produce energy more efficiently, which in turn promotes regenerative and repair processes in the cells. It is used to promote muscle regeneration, reduce inflammation, stimulate collagen production for healthier skin or to promote healing. In saunas, it is thus a complementary technology that works on a different principle than heat alone.