I will do this on a headless Rpi Zero W.  

First I am going to install a headless Raspian Stretech lite.  Directions for this are here:

https://howtoraspberrypi.com/how-to-raspberry-pi-headless-setup/

Next I will setup the software for the Purethermal2 to work with the RPi.  I will first install libusb and then the groupgets version of libuvc (https://github.com/groupgets/libuvc) and then I will try the uvc-radiometry.py script from (https://github.com/groupgets/purethermal1-uvc-capture).

Once I get the image capture to work, we will save power by periodically disconnecting from and turning off the Purethermal board which is a usb device.  There are some forums that discuss generally how this is done:

https://www.raspberrypi.org/forums/viewtopic.php?t=134351

Another approach would be to work on doing a better job at stopping camera streaming when we are done.

https://int80k.com/libuvc/doc/group__streaming.html

General power saving tips are discussed here.