The term is also used in cars, the wall separating the engine compartment from the passenger cabin. The wiki [1] says: The name originates from steam-powered v

The term is also used in cars, the wall separating the engine compartment from the passenger cabin. The wiki [1] says: The name originates from steam-powered vehicles, where the firewall separated the driver from the fire heating the boiler. [1]: https://en.wikipedia.org/wiki/Firewall_(engine) https://en.wikipedia.org/wiki/Firewall_(engine)