What is the first step in conducting overhaul of a vehicle after a fire is extinguished?

When conducting overhaul of a vehicle after a fire has been extinguished, chocking the wheels is the most critical initial step. This action provides stability and prevents any movement of the vehicle, ensuring the safety of the personnel involved in the overhaul process. Given that a vehicle may have experienced significant structural damage from the fire, securing it prevents any unintended rolling or shifting that could put firefighters at risk.

Once the vehicle is stabilized with chocks, firefighters can proceed with other tasks such as accessing the engine compartment or the cargo area. These actions must be carried out safely, as there may still be residual hazards present after the fire has been put out. By prioritizing the stabilization of the vehicle first, firefighters create a safe working environment to carry out subsequent overhaul operations effectively.