Do airplanes have sensors to detect landing gear fires? Given that retracting a landing gear that happens to be on fire is a suicidally bad idea, for reasons that should be immediately obvious, do airplanes have temperature sensors on their landing gear in order to detect landing gear fires and prevent burning landing gear from being retracted?
There are fire detection heat sensing loops in the gear well.  If a gear was on fire it would trigger a "GEAR OVERHEAT" message and warning when the gear was up.  There are no retraction prevention systems that are able to detect fires at the gear.  Nationair was a unique series of clusterflarks leading to the accident, on top of the fact that the magnesium wheels started to burn.  Modern magnesium alloys don't do that.