The Mobotix M15 with Thermal sensor is a great product but what situations require a thermal solution?  Thermal cameras work by detecting heat and thus can tell if a person is in the image by the heat radiated off us humans (I assume all reading this are human anyway).  Perimeter protection is an obvious application but other applications include anywhere detecting temperature is desirable.

Firefighters can use them to develop a better plan for fighting fires by being able to identify the location of the fire or the extent of it.  It can also be helpful in identifying hidden fires such as those behind walls.  They can also use them to help verify the number of victims in a vehicle collision.

Electrical systems can benefit from inspection by thermal imagers.  Excessive heat in an electrical component is due to excessive resistance.  This can be because of a loose or corroded connection or too much load being placed on the system.  Thermal is well suited to identify these issues.

Another application is in Building inspections.  It is quite easy to determine bad windows for example by looking at the heat being generated from each and identifying those that are much warmer than the others.  This is also applicable to roof inspection by determining where bad tiles or thin tar is on a roof.

Any system where heat or cold is an indication of a problem is a good application.  Mechanical systems that inherently generate heat are an obvious candidate.  I know of one company using them to watch wind turbines to identify problems early on for example.

The bottom line is there are many applications in which Thermal can provide an advantage.  Although I listed a few above there are obviously many more.  Hopefully this gives you an idea of where you can begin using it.