Secondary and Vicarious Trauma
One Page Handout on Secondary and Vicarious Trauma. People who work in helping professions "are called to respond to individual, community, national, and even international crises. Health care professionals, social service workers, teachers, attorneys, police officers, firefighters, clergy, airline and other transportation staff, disaster site clean-up crews, and others who offer assistance at the time of the event or later, may be negatively affected by their contact with these events."
This is a list of prevention suggestions that were developed for clinicians so it may not apply well to field-workers. Feel free to edit it as you like.
This is a brief article from the ISTSS StressPoints that outlines the general theory of Secondary Traumatic Stress and some ideas about prevention through technology- mediated support.