It's just physics unfortunately. You might be able to use an IR camera to take a "Picture" of the ambient temperature and kind of take a stab at guessing, but a

It's just physics unfortunately. You might be able to use an IR camera to take a "Picture" of the ambient temperature and kind of take a stab at guessing, but a simple thermocouple is never going to be able to do what you are asking of it. However, that won't stop Garmin from selling one to you!