When Louis Pasteur was working on the rabies vaccine, if he or his assistants got infected, they were to be shot in the head.
In the late nineteenth century, Louis Pasteur's laboratory assistants made sure to always have a loaded gun on hand. Their boss, who was already famous for his revolutionary work on food safety, had turned his attention to rabies. Since the infectious agent—later identified as a virus—was too small to be isolated at the time, the only way to study the disease was to keep a steady of supply of infected animals in the basement of the Parisian lab.
As part of their research, Pasteur and his assistants routinely pinned down rabid dogs and collected vials of their foamy saliva. The risk of losing control of these animals loomed large, but the bullets in the revolver weren't intended for the dogs. Rather, if one of the assistants was bitten, his colleagues were under orders to shoot him in the head.