The basic idea is to use CERT to safely perform many of the large number of tasks needed in emergencies until trained professional responders arrive on the scene, and even afterwards in order to free professional responders for the most technical and dangerous tasks. Much of CERT training concerns the Incident Command System and organization, so CERT members fit easily into larger command structures.
CERT teams deploy when an emergency hits their locality and also to help other localities, when requested. CERT leaders communicate via amateur radio, FRS, GMRS or MURS radio and by runner.
CERT teams perform data gathering, especially to locate mass-casualties requiring professional response, or situations requiring professional rescues, as well as simple fire-fighting tasks (for example, small fires, turning off gas), light search and rescue, damage evaluation of structures, triage and first aid. In the longer term, CERTs may assist in the evacuation of residents, or assist with setting up a neighborhood shelter or morgue.