The medical versions are different. They're not just reporting the actual surface temperature of the user's forehead. (Which is going to be a few degrees lower

The medical versions are different. They're not just reporting the actual surface temperature of the user's forehead. (Which is going to be a few degrees lower than core body temp) They compensate. I have an iHealth unit that Wyze was selling a few months ago. I check my temperature several times a day. I believe it's quite accurate. In the mornings it'll read 98.2˚F, afternoons I'm at 98.4˚F, and just before bed it'll read either 98.4˚F or 98.6˚F. The fact that it's this consistent with the intraday variation gives me some confidence in it. But, granted, I have yet to have a fever. (That I know of!) I'm not sure what it uses to arrive at the answer. It could be as simple as adding a fixed constant or multiplier to the forehead surface temperature. Or it could separately measure the ambient temperature and factor that into the radiant heat coming from my forehead to arrive at an answer.