Please add core temperature as a METRIC. I don't use a temperature sensor, but I know when my core temperature is elevated. The metric would be for general tracking, e.g. normal, elevated, lower than normal.

My core temp varies greatly throughout my menstrual cycle, and when it's high -- which can be for three weeks or more -- average HR can be up to 20 bpm higher, I can't hydrate enough, and training is compromised: an 'easy' 45 min run is often an effortful slog that leaves me feeling wiped out the next day.