A thermal imaging camera (colloquially known as a TIC) is a type of thermographic camera used in firefighting. By rendering infrared radiation as visible light, such cameras allow firefighters to see areas of heat through smoke, darkness, or heat-permeable barriers. Thermal imaging cameras are typically handheld, but may be helmet-mounted. They are constructed using heat- and water-resistant housings, and ruggedized to withstand the hazards of fireground operations.
While they are expensive pieces of equipment, their popularity and adoption by firefighters in the United States is increasing markedly due to the increased availability of government equipment grants following the September 11 attacks in 2001. Thermal imaging cameras pick up body heat, and they are normally used in cases where people are trapped where rescuers cannot find them.
A thermal imaging camera consists of five components: an optic system, detector, amplifier, signal processing, and display. Fire-service specific thermal imaging cameras incorporate these components in a heat-resistant, ruggedized, and waterproof housing. These parts work together to render infrared radiation, such as that given off by warm objects or flames, into a visible light representation in real time.
The camera display shows infrared output differentials, so two objects with the same temperature will appear to be the same "color". Many thermal imaging cameras use grayscale to represent normal temperature objects, but highlight dangerously hot surfaces in different colors.
Cameras may be handheld or helmet-mounted. A handheld camera requires one hand to position and operate, leaving only one free hand for other tasks, but can be easily transferred between firefighters. The majority of thermal imaging cameras in use in the fire service are handheld models.
The National Institute of Standards and Technology Fire Research division is the lead government agency developing performance standards for fire service thermal imaging cameras in the United States, although the U.S. Army Night Vision Laboratory has contributed to the effort. Preliminary recommendations from the field include visible low-battery warnings, ability to withstand full immersion in water, and the ability to provide meaningful visual readouts beyond 2,000 °F (~1,100 °C).