They protect the combustible framing by cladding it in fire-resistant materials like gypsum boards.
Fire code is an integrated and elaborate part of the building code.
It assigns fire protection requirements and demands fire ratings of structure and its contents depending on the usage and location of the building.
It sets standards for access and egress and fire escape routes.
It sets ratings like how long a gypsum board should resit a fire of a predesigned intensity. what class and rating windows and doors and roofs should be. it assigns higher protection to more critical components of the building. it requires a fire hose connection at hallways and landings. it requires sprinkler systems in certain buildings. It sets the size and location of fire-stop partitions and automatic lock-off fire gates in large areas.
It is a multi-faceted all-encompassing system of regulations involving from conceptual design to routine post-construction fire inspection to accessibility to water and fire hydrants and location of fire departments.
The fire department can and has issued non-conforming citations and ordered the buildings in violation of the code to be declared unsafe and to be vacated till fixed.
Here is a detail for an exterior two-hour fire rated wall.