A new project has transformed the Raspberry Pi into a thermal imaging camera. Using the housing of a discarded microwave detector, the Apollo Pi Thermal Camera is based around a Raspberry Pi Zero W, a 1.3-inch display and a Thermal Camera Breakout.
https://www.notebookcheck.net/Raspberry-Pi-Turn-the-popular-single-board-computer-into-an-inexpensive-thermal-camera.462262.0.html