Nick, I mentioned some locations on Mars that had high THEMIS "brightness temperatures" here:

Martian high north latitude hot spots?
Robert Clark
Posted: August 4, 2005 11:30 PM
http://www.marsroverblog.com/discuss-27650-martian-high-north-latitude-hot-spots.html

However, brightness temperature does not directly correspond to actual surface temperature. Factors that can influence it are atmospheric properties and the albedo of the surface. Since these locations are at high latitude, a high albedo could have come from surface ice, which would give a misleadingly high brightness temperature. Since sulfate deposits have been widespread on Mars, the presence of light colored sulfates might also cause an usually high brightness temperature.
I would like to see a connection between high resolution HiRise images and high resolution CRISM spectra of these regions specifically at where the maximal brightness temperatures occur to see they give indications of vents or fissures and if the spectra show ice or sulfates.

Bob Clark