Thermography - Making the Invisible visible

Above absolute zero (-273°C) all objects emit thermal infrared energy. As long as the object is radiating at a higher temperature than its surroubndings, energy transfer will be taking place and energy will be radiating from warm to cold following the principle stated in the 2nd law of Thermodynamics.
Thermal imaging allows to detect radiation in the infrared range of the electomagnetic spectrum, and produces images of that radiation. Warm objects stand out against cooler backgrounds. Humans become visible against the environment even after death. The amount of radiation emitted, however, decreases with falling temperature.
Thermal imaging sees objects regardless of the ambient light and makes it possible to see phenomena otherwise impossible to detect with the human eye.