The thermal imager is also called a forward looking infrared device. It can detect infrared radiation emitted from an object and convert its readings into a two-dimensional, black-and-white picture. The military has used it for years on the battlefield. Law enforcement has started using the device only recently for search and rescue operations, fugitive apprehensions, and the detection of drug smugglers along the border. Thermal imagers have been particularly helpful, although controversial, in the detection of indoor marijuana-growing operations. Most courts that have examined the use of the imagers have decided that targeting a building with a thermal imager is not a search under the Fourth Amendment. However, it is impossible to predict if or when the U.S. Supreme Court will resolve the debate over the warrantless use of this technology. Therefore, police officers should consult their legal advisors to determine whether a search warrant is required to use a thermal imager in their jurisdictions. The results of a thermal scan provide only one of many types of facts that the officer must combine into the mix of probable cause to obtain a search warrant and search the building. Officers should also ensure that a scan is conducted from a location where they have authority to be. They should also clearly document the capabilities of their machines. Photographs and reference notes