"Al" wrote...
My O2 system I set to not even give me a puff of O2 till over 12,000ft
I use the M+H EDS set to D12 setting. You must be really infirm to get
hypoxic at just over 11k do you smoke or are you very old?

Uh, Al, you live at 6000+ feet. You are aclimated to a reduced partial pressure
of oxygen. Those of us who live closer to sea level take a few days to get to
that state. I have felt symptoms of hypoxia at lower altitudes, when I've
driven up to Truckee from the Bay Area and flown the same day. As far as I can
tell, I'm not infirm, I don't smoke, and I'm not quite elderly, yet. I use
oxygen from ground level every flight at Truckee, Minden, etc., it's cheap
compared to the alternative...

Marc