What objects emit infrared light? What technology exploits this?
Infrared radiation is a type of electromagnetic radiation, as are radio waves, ultraviolet radiation, X-rays and microwaves. Infrared (IR) light is the part of the EM spectrum that people encounter most in everyday life, although much of it goes unnoticed. It is invisible to human eyes, but people can feel it as heat.
When an object is not quite hot enough to radiate visible light, it will emit most of its energy in the infrared. For example, hot charcoal may not give off light but it does emit infrared radiation which we feel as heat. The warmer the object, the more infrared radiation it emits.
Any object above 0 kelvin will glow in a color, the hotter it is the higher is its frequency of glow.Like the sun with those huge temperatures inside of it emits ultraviolet and gamma rays, that is because there is more heat energy added but heat is not equal to infrared radiation.