hypoxia

Footage of FAA altitude chamber hypoxia training for pilots in which a participant passes out from oxygen deprivation. It shows how quickly and subtly cognition fails at altitude.

Air traffic audio of a pilot slurring and incoherent while declaring an emergency due to extreme hypoxia, with controllers at Cleveland Center struggling to understand him.

Destin Sandlin of Smarter Every Day undergoes hypoxia training and experiences his own impaired thinking as oxygen is withdrawn. The video shows how quickly and unnoticeably oxygen deprivation degrades judgment, illustrating why you put your own mask on first.