Excellent posts regarding this sometimes insidious hazard.
Someone ('cats_five')mentioned it's effect people differently. That's spot on. Also a human being at rest requires less O2 than someone dealing with an emergency at ALT, the latter requiring more, esspecially at night seeing (pun not intended) the eyes need more O2 to function correctly.
CW
p.s............hey Dr, don't forget the 'Conty' up that high, she'll be gasping also !
