Temperature gun for brakes and bearings?

Overly hot brakes aren’t the problem on a trailer that they can be on an airplane, so most folks are fine ignoring the issue until they glance in the mirror and see the wheels smoking. The main use is to make sure they all match to be sure you haven’t got a wheel bearing going bad or shoes in desperate need of readjustment. If everything is fine and you only used the brakes to stop to check them, they might be 30 degrees above ambient. If you just came down the mountain, however, they can be anything. If they are more than 200 degrees above ambient, you came down way too fast and really should have made better use of lower gears.

Most recently used mine to diagnose an electrical problem on my TV. Sheet metal next to driver’s door handle indicating a short circuit in the handle’s lock/unlock board made a 20 degree temperature difference.