Thermal image camera water leak detector
Infrared imaging detects infrared light differences across surfaces not seen by the human eye. When used as a method of water leak detection in a building the leak point may produce a cold or hot image (i.e. for cold water or hot water pipes) compared to the surrounding environment.
Thermal image has many uses beside water leak detection such as Night vision security; industrial plant maintenance inspection for overheating pumps, assess loose electrical connections or detect energy loss in buildings. Below picture from a thermal image camera showing hot and cold temperature ranges.