Tempe use in an open water swim

Thank you! So I don't think the Tempe is working then!

The value from Tempe is not supposed to be shown on the map. Assuming you paired the sensor, the temperature data is shown on the Stats tab. And if you enable the temperature recording option in the activity settings, there will be also a temperature graph on the Charts tab. You can also add a Data Field with the temperature to one of the activity screens.

See also the documentation at support.garmin.com/en-US/?faq=6feE6LD1Ir5VKudpdm9DP6 

BTW, it is unnecessary to use Tempe in water. Unlike on air, where the internal thermometer is strongly influenced by the body temperature, in water, due to the 21 times higher thermal conductivity of water, the internal sensor works accurately for measuring the water temperature, so the external sensor is redundant.

Thanks so much @trux.

I don't think the Tempe is working - no temperature readings anywhere and it never seems to connect, although it is "paired". I have a Garmin Vivoactive 5 so I don't believe it has an internal temperature sensor 

Did you pair the sensor with your Vivactive 5? Did you enable the option "Record Temperature" in the OW Swimming settings? Did you add the temperature field to one of the activity data screens? 

I have connected it (ie the serial number appears under "tempe" on the wetch), but it has never connected when I touchc""onnect 

If you post a link to one of the activities where you used Tempe, I can tell you whether it was connected or not.

Otherwise, I am not familiar with Vivoactive 5, and do not have Tempe - you may get a more relevant help on the Vivoactive 5 forum at forums.garmin.com/sports-fitness/healthandwellness/f/vivoactive-5-series or by contacting the Support directly. The only thing that I can advise, is trying to remove the sensor from the watch, pair it anew, and to change the battery if it fails to do so.