In the industry I am in, we do annual infrared surveys of all of our switchgear (breakers and contactors) These range in size from 15 amps to 1000's of amps. We use very sophisticated cameras and always find problems that were not there the year before.
You can periodically do the same thing with your infrared gun you use to check your wheel bearings and tires. Make sure the circuit you are testing is under load and shoot the breaker and corresponding neutral connection to the buss. Record your finding on a napkin but preferably on an excel spreadsheet. You'll spot trouble long before it looks like the attached photo. These problems usually do not happen over night but get worse and worse as time goes on. Add to this an RV going over a California concrete freeway and things tend to come loose.
