So are you suggesting that everyone travel with a thermal imaging device? That may be a good idea, but loses points on practicality.
For under $50 everybody can travel with a Harbor Frieght infrared temp probe. It is small, practical, and works. It can save a roadside repair by detecting a bearing problem as well as brakes that are working or not. A thermal imaging device is wonderful but for most trailering applications is probably more than needed. This has been an excellent thread and my read of the OP's concern is that however we do it the brakes should be checked to be certain they are working. Thermal imaging is only one way to do it.
