iOS 14 code reveals Apple Watch blood oxygen monitoring feature

Apple is developing at least two new health features that will expand Apple Watch capabilities. Apple Watch will add blood oxygen monitoring for the first time, 9to5Mac found in iOS 14 code.
Diagram of the back of an Apple Watch Series 5
Zac Hall for 9to5Mac:Blood oxygen levels between 95 and 100% are considered healthy; blood oxygen levels below 80% may lead to compromised heart and brain functionality. Risk of respiratory or cardiac arrest is common after continued low blood oxygen saturation.