CORE Body Temp integration
Biketerra supports the CORE Body Temperature sensor.
The CORE sensor clips onto an existing HRM (heart rate monitor) strap.
It calculates your body temperature, skin temperature, and HSI (heat strain index), which can be helpful for heat training.

Usage
After installing the CORE app (and updating firmware), it's strongly recommended to "bridge" your HRM the CORE device using the app. The CORE device needs heart rate data to provide accurate calculations.

In Biketerra, pair your CORE sensor just like you would any other Bluetooth device:

NOTE: If you've set up HR bridging from within the CORE app, you do NOT need to pair your HRM separately.
After pairing, you'll see additional metrics at the top:

- Core body temperature (Celsius)
- HSI (Heat Strain Index), starts at 0, a value beyond 7 is exceedingly rare
- Heat zone (the HSI background color, see chart below)
Heat zones

(source: CORE website)
Recording
Biketerra records body temperature, skin temperature, and HSI to the FIT file. Body temperature is an "official" FIT field, so appears automatically in Intervals.icu.
The other two fields are developer fields, meaning they aren't yet officially supported by the FIT spec. To visualize them in Intervals.icu, you need to add them as Custom Streams.
To see how to add Custom Streams in Intervals.icu, refer to the "Dual Power" section on the Intervals.icu doc page.