This device is intended to be installed within the 3D printed forehead mount of a visor.
It’s being developed at this github: https://github.com/merlinmarrs/Fever-Meter
The top board is a boost regulator taking the 2V from a pair of miniature backup batteries, and the bottom side is an attiny85 with I2C temperature sensor and indication led.
This project necessitated the use of rivets. I used a dremel to make a hole in the board then inserted the rivet and gave it a tap with our riveting tool.
The results are relatively clean: