To read the temperature and dew point right where you are. That's the whole app — without location, there's no conditions to adjust for.
Temperature plus dew point, in °F. It's a better predictor of how hard a run will feel than temperature alone — that's why 75° in a dry climate is easy and 75° somewhere humid isn't.
Goal pace is the number you set — what you'd run in ideal conditions. "Run this pace today" is what Heat recommends instead, adjusted for the current heat and humidity.
Recovery periods between intervals give your body a chance to cool down, so the pace adjustment for interval workouts is about half of what a continuous run needs.
Check your internet connection and that Location access is allowed for Heat (Settings → Privacy & Security → Location Services → Heat). Tap Retry once connected.
No. Heat has no run history, no accounts, and no server — it only ever shows today's conditions and today's pace.