Say what?Would be dead before I even arrived as the oxygen in a planes pressurised cabin is partially depleted due to it being recycled. The risk of infection is also too high and mu insurance wont cover the costs of a "hospital medivac plane"
Yes, some air is recycled, but that's because it's sub-zero outside and the recycled air helps warm it up. The oxygen level is just fine. However, due to engineering, the cabin pressure at cruising altitudes in the high 30s to low 40s is about 8000'. Yes, the oxygen content is reduced just like being on one of the foothills near Denver or any other 8000' mountain. It's due to "cabin altitude", not "due to it being recycled".