Acute - =Sharp or severe having a rapid onset and short duration. -All-Hazard Concept - =Provides a coordinated approach to a wide variety of incidents; all responders use a similar, coordinated approach with a common set of authorities, protections, and resources. -Atypically Stressful Event - =Term used in National Fire Protection Association (NFPA) standards to describe incidents that have a likelihood of causing critical incident stress. -Battalion - =Fire department organizational subdivision consisting of several fire service companies in a designated geographic area. A battalion is usually the first organizational level above individual companies or stations. -Body Substance Isolation (BSI) - =Comprehensive method of infection control in which every patient is assumed to be infected;