This is a similar idea to the temporal arterty thermometer, which uses an infrared camera: https://en.wikipedia.org/wiki/Medical_thermometer#Temporal_artery htt

This is a similar idea to the temporal arterty thermometer, which uses an infrared camera: https://en.wikipedia.org/wiki/Medical_thermometer#Temporal_artery https://en.wikipedia.org/wiki/Medical_thermometer#Temporal_a... The mathematical model for the sensor is probably different, though.