Warriors on the modern battlefield face considerable danger from possible attack with chemical and biological weapons. Aggravating this danger is the fact that medical resources at the lowest echelons of care, already likely to be strained to capacity during modern conventional combat, are at present inadequate to handle large numbers of chemical or biological casualties. Complicating this problem further is the austere nature of diagnostic modalities available at lower echelons. With this in mind, and given the urgency required to adequately manage chemical and biological casualties, it is likely that such casualties will initially require significant empiric care in the absence of a definitive diagnosis. Such care under field conditions, often rendered by relatively inexperienced medical personnel, might best be provided using an algorithmic approach. We have developed such an algorithm.