On older watches, that only has the temperature if a tempe is connected, On Edge devices that don't support a Tempe, it's internal.
With current watches, it will switch between internal and Tempe (say the tempe disconnects and reconnects). It's similar to other sensors and you see "best source:" as you do for cadence when a footpod is involved
With Temperature,and a Tempe, that only updates once a minute, while for internal it can be much more often (every second), so you can tell by displaying it and if it's fast or slow. Maybe you could add some code to look for that. I played around with that, but there were times the internal temperature didn't actually change that often
Ok, that's an idea, that might be able to differentiate in some cases. I hoped there might be something in the SDK that I missed or that there's some trick maybe using Sensor.something. Obviously the watch does know it, it even displays it in the beginning of an activity: when I still wait for the GPS to lock there's also a blinking thermometer icon.
You'll see internal while it's looking for a paired tempe. That connection process can take a minute or more for a DF or a device app/super app.. These times help the battery in a Tempe to last a year or more while it's running 24/7
Oh, and what you see for the heading in Sensor can vary based on the speed as well as if GPS is being used,
With a watch, if the user is stopped, the heading reflects how the watch is pointing using the compass, while when moving it shows the direction being traveled (from GPS). If I recall, it changes when the speed is greater than 2mph.
Also note that there's no internal temperate on devices without a baro altimeter like vivoactive 5.
While I'm talking about things other than temperature, they all go back to "best source" when multiple sources can be involved.
