The term “hot zone” generally refers to any dangerous location. Entering such a location often requires protective clothing, elevated security clearances and highly specialized training. In medical usage, the term refers to a location where personnel work with organisms that are particularly dangerous.
Officials generally classify this type of area as a high-level biohazard area. The term may also refer to a location where patients receive treatment for a contagious disease.
In industrial settings, a hot zone is a location where hazardous materials are present. The Environmental Protection Agency defines a hot zone as an area where there is a risk of contact or exposure to a hazardous substance or the area that poses the greatest potential risk of exposure.
The term "hot zone" originated during the Cold War to refer to an area that was active with nuclear radiation. Author Richard Preston popularized the term in his 1994 book, “The Hot Zone,” which describes the origins of the Ebola and Marburg viruses.