Most of the fixtures have the same white color of OLED and are very expensive, but quite dramatic.The OLEDs are cool to the touch and, unlike LEDs, are a uniform light emitting surface rather than a point source that is then diffused, giving the light a very different character. (treehugger.com)
Infrared saunas use charcoal, carbon fiber, or other types of emitting surfaces to deliver infrared heat. (myersdetox.com)
The intensity and distribution of radiant energy within this range is governed by the temperature of the emitting surface. (britannica.com)