A fire engine responds on every ambulance call for several reasons. With both units being dispatched, you will get the fastest possible response. The ambulance may not be the closest unit or may be on another call, and the engine is paramedic-equipped to begin treatment while an ambulance is en route. Secondly, in order to perform the quality of service one would expect, a minimum crew of five paramedics are needed on each ambulance call, as there are many tasks to perform, from patient treatment to patient movement to the ambulance for transportation to the emergency room. If the fire engine crew is not needed, they can always be called off by the ambulance.