There are a few things to consider with respect to data from the CORE sensor
For the most accurate results, the CORE sensor should be worn before starting an activity (at least 10 minutes before).
The moment the CORE sensor starts to get valid data, it will quickly be able to record and broadcast skin temperature and this updated every 2 seconds.
When the CORE sensor is first worn, it can take up to 2 minutes to calculate the core temperature.
As long as you are wearing CORE correctly, the measurement will update every minute with your real-time core body temperature.
If CORE receives invalid data e.g. it is worn incorrectly or not on the body at all, it will take longer before it will deliver a valid core temperature after you start wearing CORE correctly.