Do people glow in the dark? They do in the infrared! Infrared is mainly heat radiation and all warm-blooded animals, including humans, generate their own heat. The heat that our bodies emit peaks in the infrared at a wavelength of about 10 microns (1 micron = 1 micrometer or 0.000001 meters). The images shown below were taken by a thermal infrared camera which translates the infrared radiation emitted by these people into visible light colors which we can see with our eyes. The brightest areas are the warmest while the darkest areas are the coolest. Notice how some people have cold noses, while others have cold lips. Different areas of skin appear warmer or cooler depending on how close blood vessels are to the surface of the skin. The clear glasses worn by several people in this gallery appear dark because infrared cannot penetrate easily through glass or certain types of plastic. Even if these images were taken in a pitch dark room, they would appear the same because all of us glow in the infrared!