How to change the measurement unit? Sylvain 28 August 2019 14:29 Updated Follow Press the START button to turn on the device. Press the mode setting button to switch between measurement modes (body temperature, surface temperature, room temperature) and choose the desired unit (° C, ° F). Press START to confirm your choice. Related articles How to mute/turn on the sound? How to change mode? How to measure forehead temperature? Comments 0 comments Please sign in to leave a comment.