When a fire is beyond the control of the on duty shift or if two fires take place at the same time off duty fire fighters are called back to duty. The number of fire fighters recalled will be determined by the commanding chief and is based on the nature of the incident. In many cases the off duty fire fighters are called to provide the city with coverage using reserve apparatus when all the available units are committed to an incident.
The department operates one reserve fire engine. This unit is kept in a state of ready reserve for use when regularly assigned equipment breaks down, or for use in a major emergency by off duty fire fighters.
If an incident grows to a point where the Bay City Fire Operations Division cannot control it then help can be requested from any fire department in Bay County, the City of Midland, or the City of Saginaw under mutual aid agreements. These communities can also request aid from Bay City.