Heating is seen around the cables on this connection unit. it is unlikely that this would be found under normal maintenance procedures.
This shows heating of lighting circuits on a distribution board. Additional circuits are often added to distribution boards without any consideration of the loading of the board, the thermal image shows the overheating which is occurring.
Heating can clearly be seen on the top and bottom of this MCB. Poor terminations are often a cause of such problems.
This shows heating in a contactor. The surface temperature and heating profile give a good indication of whether an item is operating within its correct parameters.