“McMaster researchers, working with partners at other universities, have created a motion-powered, fireproof sensor that can track the movements of firefighters, steelworkers, miners and others who work in high-risk environments where they cannot always be seen.

The low-cost sensor is about the size of a button-cell watch battery and can…”

Source: https://www.eurekalert.org/pub_releases/2019-03/mu-tfi030119.php