This is a tiny little resistor on the left hand side of the board close to the reset switch header. It's not spectacularly hot but it does stand out a bit. Mind you, being a resistor it is probably supposed to be hot and it is exceptionally tiny, therefore if you ever consider heat sinking this, even for a moment, you would probably be advised to attend the next meeting of Heatsinkers Anonymous.

Note that the small hot spot to the left of this is actually a reflection in the metal case side. Relfections are one of the things us thermographers have to watch out for all the time you know.