Another interesting case is:

THEMIS Image Data Page for I02026005.
CENTER_LATITUDE = 39.1376
CENTER_LONGITUDE = 251.959
MINIMUM_BRIGHTNESS_TEMPERATURE = 302.213
MAXIMUM_BRIGHTNESS_TEMPERATURE = 322.192
http://themis-data.asu.edu/img/I02026005

This happens to lie in Alba Patera, the volcanic region. This image is
much more free of noise making it more likely the measurement is an
accurate one.
Here's a visible light image:

THEMIS Image Data Page for V02026006.
http://themis-data.asu.edu/img/V02026006

Again it would be interesting to find out if the highest temperature in
the IR image is reached where there is physical or geomorphological evidence of
a vent the visible light images, such as a pseudocrater for example.

Bob Clark