Firefighters’ safety during fire responses depends on sound policies and procedures that ensure they can do their jobs efficiently and effectively. Decisions on vehicle crew size and total effective response force deployment should be based on the best available evidence. It is imperative that fire depart- ment leaders and political decision makers understand how the fire department resource deploy- ment impacts community safety related to civilian injury and death, firefighter injury and death, and property loss. This state-of-the-art review provides a comprehensive examination of (a) results from multidisciplinary (e.g., engineering, medicine, fire technology, and social sciences) research efforts, (b) published data, (c) industry standards, and (d) expert opinion. The review examines the effect of emergency response vehicle crew size and total effective response force deployment on firefight- ers’ health and safety risks, recognizing that firefighter health and safety is necessary to ensure that firefighters can effectively perform their jobs and protect their community. We conclude, based on available evidence, that the crew sizes and the effective response force sizes recommended in NFPA 1710, Standard for the Organization and Deployment of Fire Suppression Operations, Emergency Medi- cal Operations, and Special Operations to the Public by Career Fire Departments, should be considered the minimum to provide for firefighters' health and safety. Whenever possible, additional resources should be provided to address firefighter physiological stress, limit fire growth, and mitigate occupa- tional exposure in today’s rapidly evolving fireground.