What might help is to locate where these maximal temperatures are occurring within the image and try to relate them to geomorphology in visible light images.
It would also help to find out if these high temperatures are maintained in subsequent IR imaging.

It is interesting that one of the images lies within Cydonia:

THEMIS Image Data Page for I02834003.
CENTER_LATITUDE = 40.1813
CENTER_LONGITUDE = 349.993
MINIMUM_BRIGHTNESS_TEMPERATURE = 306.029
MAXIMUM_BRIGHTNESS_TEMPERATURE = 322.379
http://themis-data.asu.edu/img/I02834003

and contains a feature that has been claimed to appear as a "smoking pyramid". It's an area in visible light imaging that has light colored areas giving the appearance of gas or water vapor release. It would be interesting to find out if the maximal temperature in the IR image corresponds to this "smoking pyramid".
Some visible light images of the region:

MOC narrow-angle image E01-01908.
http://barsoom.msss.com/moc_gallery/e01_e06/images/E01/E0101908.html

THEMIS Image Data Page for V02834004.
http://themis-data.asu.edu/img/V02834004.html

Bob Clark