If a brake overheats on an aircraft there is a very real danger of the increased heat causing the tyre to explode for this reason aircraft wheels are fitted with special fusible plugs that release the tyre pressure if the wheels heat up too much.
Wheel/brake-area fires on the other hand are typically caused by a buildup of grease or oil on the axle during service or the application of excessive amounts of grease during wheel/tire changes and brake installation or a hydraulic leak and the presence of a heat source, namely the brakes. For this reason aircraft wheels are filled with nitrogen so if there is a fire they will not feed the fire if the fusible plugs let go
Author – Paul
