How to check your heart rate on an Apple Watch

Yes, you can get notifications if your heart rate gets too high during inactivity, with options to get warnings if your heart rate goes over 100BPM, 110BPM, 120BPM, 130BPM, 140BPM or 150BPM.

Yes, using the Health app on the iPhone you can access the same information that is on the Apple Watch. You can also find more in-depth information on the iPhone, like your daily and weekly average heart rate.