Here’s a YouTube short from Hank’s Channel that explains why you don’t know you’re being asphyxiated by pure nitrogen.
The reason I’m bringing this up is that a few years ago some guy poured a giant dewar flask of liquid nitrogen into the swimming pool at a party. So some people commented about this on Facebook. I said that they should be careful because the lack of oxygen could cause someone in the pool to die.
And I caught hell from others about that. They said it was safe and the nitrogen wouldn’t hurt anyone. Then Hank explained that your body doesn’t sense that there is no more oxygen in the air, and you can just pass out and die. If you’re deprived of oxygen for more than a few minutes your brain cells die and you become a vegetable. Your brain has no activity. That’s brain death. And what’s worse is there is no warning whatsoever.