While I was testing a factory office, a double adaptor was tested. Although it passed minimum requirements to be tagged, the readings were higher than expected.
I used a thermal imaging camera to view the adaptor while in use. It showed the inner workings of the adaptor running at a significantly higher temperature than normal - creating a potential fire risk. I showed the client the image and the adaptor was discarded immediately.
This shows how regular testing and having thermal imagery available can prevent catastrophic problems for your business.