I wasn't aware of this system, does it just have an automatic alarm if temperature is above a certain level, or do they have operators looking at thermal camera images for heat in unexpected places - I expect the latter to be much more likely to pick something up but obviously costly in staff time
It shouldn't be hard to set up an automatic monitoring system to work with feeds from thermal imaging cameras.From memory (happy to be corrected if I'm remembering wrongly), catalytic converters and diesel particulate filters that are in regen mode can easily hit 500C and higher. That would make it very difficult to distinguish between normal high temperature components and the beginnings of a fire. Equally, those very hot parts of the exhaust system can be the cause of a fire if something comes in contact with them before they cool, which is why most vehicles carry a warning in the handbook not to park on long dry grass, or otherwise park where combustable material can come in contact with the exhaust.
The code involved would be quite similar to that used in a video editing program to pick out levels that are not broadcast safe (TV has a restricted dynamic range compared to cinema, the main reason that movies always look worse on TV) and could easily be programmed with different alert thresholds for different segments of the field of view as appropriate.