https://www.wired.com/story/can-an-infrared-camera-detect-a-fever/

One of the coolest things about infrared cameras is that you can point them at a scene and get a visual image of how hot or cold things are. So … what if those things are humans? Could you use an IR camera, for instance, to check people at an airplane gate for possible Covid-19 fevers?

On the plus side, it wouldn’t require any physical contact, and you get an almost instantaneous reading. Actually, you might have seen pictures of handheld IR devices called temperature guns (which work somewhat differently) used like this in China. IR sensors are also used in factories to monitor the temperature of equipment without having to stop it.