Figure 2. Approach to triage and therapy for persons exposed to radiation in a limited-casualty scenario. A numeric degree of severity is assigned for the cutaneous, gastrointestinal (GI), neurovascular, and hematopoietic systems, as defined in Tables 2 and 3. The highest degree of toxicity to an organ system indicates the physiologic "response category" (that is, 1, 2, 3, or 4). Modified with permission from reference 24.