This are infrared images but not thermal images (8.000 to 14.000 nm).
More like IR-B/MWIR from here -
As i said in the article, Near Infrared from the silicon graph is really easy to get to - all you need is to do some surgery on a regular camera.
Going below is where the tricky stuff starts.
The images that the Thermasnap produces are very good, but it can only image non moving objects or scenes. It was designed to be a more affordable thermal camera solution.
I can't seem to find what the resolution is. Do you happen to know?
My rig is, theoretically, 2400x1200, but tough luck getting it focused to that limit.
The frame time would be about 30 minutes at full resolution, so i usually do 5 minute snaps at a much lower X one.
Anyway, while their concept is faster, it relies on an even more exotic part - a thermal linear CCD, so i haven't really considered making something like that.