If patients are in shape to be on the phone why do they feel the need to put in a breathing tube?? I have measured my O2 saturation being in the 80s and my rea

If patients are in shape to be on the phone why do they feel the need to put in a breathing tube?? I have measured my O2 saturation being in the 80s and my reaction was "so that's the effect of being this high up"--and I continued to head up the mountain. I had been there before, I knew I wasn't getting into too much. (I forgot to check on the summit itself. I don't expect to be there this year but I'm going to check again next year.)