Why You Should Put YOUR MASK On First (My Brain Without Oxygen) - Smarter Every Day 157

> so that we can detect the symptoms of hypoxia particular to our own bodies Destin of SmarterEveryDay (with astronaut Don Pettit) recorded his experience with that training, which included a demonstration of the effects of hypoxia on his decision making ability. He doesn't notice the rapidly increasing symptoms: >> [Destin fails child's shape toy test, saying the cross was a square] "Alright you're starting to have a little shake there, you know from your lack of oxygen. You need to start thinking about getting back on oxygen now Destin." >> "How would you correct for that? Can you correct for hypoxia for me?" [Destin just sits looking confused] "Alright sir if you don't get on oxygen, you're going to die. Go to your regulator, get all three switches on your regulator..." [Destin looking even more confused: "I don't want to die"] >> [they get him back on O2, fixing everything in seconds] [this video]

There's an interesting caveat here, the phenomenon is well known to apnea practitioners: - Hyperventilating, then holding your breath underwater can easily be deadly. - Doing the same without hyperventilation is much safer. The difference lies in the fact that our ability to sense our limits are almost entirely due to CO2 buildup. We actually almost can't tell when we run out of oxygen, it's why pilots are fine one second and pass out the next when they don't notice that the oxygen runs out ( [this video] ). Hyperventilating reduces your CO2 but leaves oxygen saturation almost unaffected, which for an unexperienced person is equivalent to doing a blind walk next to a cliff, and removing the barrier.