The temperature offset is uncalibrated so the absolute temperature isn't that great, but if you figure out the offset by getting the temperature when you know the Bangle's temperature then it should be reasonably good.
And easiest would be to ensure you got the temperature when the Bangle had been idle for a while and you should be ok - but even flat out the nRF52 only draws around 10mA, so it's not going to be able to warm itself up too much
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
The temperature offset is uncalibrated so the absolute temperature isn't that great, but if you figure out the offset by getting the temperature when you know the Bangle's temperature then it should be reasonably good.
And easiest would be to ensure you got the temperature when the Bangle had been idle for a while and you should be ok - but even flat out the nRF52 only draws around 10mA, so it's not going to be able to warm itself up too much