Even if you don't use a thermal camera, just the thermal thermometers work as well. Sure, you have to take more readings, but the result is the same. A lot of people probably have one of these now after Covid, and can at least test things out before going to the step of a full thermal camera.

I have a bedroom that has a shared wall with a water heater which causes this room to be hotter than the rest of the house. Using the thermometer showed the temps after I added a barrier to the inside of the utility closest dropped significantly.