Assessment and management of CBRN casualties is complex because it involves not only life-threatening symptoms but also the threat of contamination of all first responders. An added source of complexity is the frequent mixing of CBRN and penetrating trauma injuries (Figure 3). Working through this complexity involves a stepwise approach that first rules in or rules out CBRN injuries so that first responders can protect themselves if necessary before rendering aid. The next step integrates assessment and management of both CBRN and traumatic injuries, prioritizing the recognition and management of life-threats first.