I work at the Houston Museum of Natural Science and we have an exhibit in our Wiess Energy Hall that demonstrates thermal energy. It has been in place for 13+ years and the imager gave up the ghost. All of the replacements were > $5K; well above the repair budget. So, the search was on...
Thermal imaging uses long wave infrared that requires a specific sensor. Normal digital cameras have an infrared (IR) filter. Some of these can be "easily" removed, but the sensor only picks up short wave infrared. It can indicate large temperature differences, for example between room temperature and a lit candle, however it has issues with small differences like people and a room temperature wall or floor.
The first option that came up was the FLIR ONE. They appear to be good, but require an iPhone 5. We didn't need high resolution so the 60 x 80 format would have worked. It would have been a solution for $250, an iPhone5, and some way to display on a big screen.
The second option is from Seek Thermal. They have models for Apple (lightning) and Android (micro usb). I got the usb version online for $200. It has a 206 x 156 array; more than 6 times the resolution of the FLIR, better interface options, and lower price. Hmmmmm, which one did I test?! You can search online for a lot more details I won't list.
The plan is to use an older phone that has an HDMI output or an ODroid board to drive the exhibit. Their software didn't immediately work on those, but they have a development kit on the way. :)
So, back to the device. Clearly, it works. The first drawback was that micro usb is a directional connector. The Samsung phones cause it to point in the correct direction. On my HTC One, it takes great selfies! The solution is a short cable that also allows more flexibility. Another drawback is that it is a hungry little device. I haven't done any specific testing, but normally I'll have 40-50% battery at the end of the day. After testing yesterday, I was at 15% last night.
Of course, I had to test it on my hive. Ambient temperature was about 56F for all of these pictures. I tried it last night, but the 4x4's I use for a stand held a lot of heat. I took a few more shots this morning so you could see the setup in visible light for comparison. I'm considering getting one for my own usage to find hives behind drywall for less destruction on removals. It looks like it would do well for quick checks on cluster presence and location also.
Disclaimer: I don't work for or have any stock in these imaging companies. The opinions are my own and do not represent The Houston Museum of Natural Science. They are for informational purposes only.