All this advice is saying is for a person with symptoms to ask Hatzala or a doctor to measure their oxygen level, even before they have difficulty breathing. This is good advice and not something that needs to come from a doctor. There is no downside. My father had the virus and Hatzala checked his oxygen and it was lower than normal. He spent a few days in the hospital on oxygen and some other midicines and is back home and recovering now.
