Ah, my bad. Likely dependent on the individual. Found this [0] interesting as it’s focused on aviation rather than climbing: > 10,000 feet. Night vision is now

Ah, my bad. Likely dependent on the individual. Found this [0] interesting as it’s focused on aviation rather than climbing: > 10,000 feet. Night vision is now degraded by 15-25 percent. The blood saturation has dropped to 90 percent and your brain is receiving the absolute minimum supply of oxygen. This is the absolute highest altitude at which you should haveany trust at all in your own performance although your judgment is already severely compromised. Euphoria will prevent true self-assessment of your abilities. Physical hypoxic symptoms such as tingling and headache may not become apparent for four hours ormore at this altitude, although judgment has long gone by the wayside. Above 10,000 feetblood oxygen saturation and performance degrade steeply. > 14,000 feet. Blood oxygen saturation is down to a dangerous85%. You will be increasingly disabled at this altitude. Vision will dim. You willexperience serious degradation of judgment, memory and thought. The impairment of judgmentwill leave you feeling just fine and confident in your performance, however. If hypoxia isnot recognized and corrected at this stage of impairment, it is unlikely that it will berecognized. You are in serious danger. 16,000 feet. Only 2,000 feet higher than the last assessment, but you will behave as though you had ingested a full load of gin and tonics. Your blood oxygen saturation will have dropped to 79 percent and you will be seriously disabled. Youwill be euphoric, belligerent, disoriented or perhaps all three. You will be irrational,unreliable and dangerous. If you are alone, your chances of survival are decreasingrapidly. > 18,000 feet. At this altitude you are incapable of any usefulfunction although you may still feel great! Blood saturation has fallen to 71 percent andyour brain is suffering. You will pass out in about 30 minutes. > 20,000 feet. If you have not already collapsed, it will not belong now. Five to 15 minutes is about the time of useful consciousness at this altitude and prolonged exposure can result in death. Blood saturation has dropped to 71%. > 25,000 feet. Forget it! Blood saturation has now dropped to lethal levels. Time of useful consciousness is three to six minutes with death followingnot long after that. Above this altitude, suffering a rapid decompression may also result in a condition divers know as the bends and various other pressure related maladies. Remember, this is only HALF as high as some modern civilian aircraft are certified to fly! [0] https://www.avweb.com/flight-safety/when-humans-fly-high-what-pilots-should-know-about-high-altitude-physiology-hypoxia-and-rapid-decompression/ https://www.avweb.com/flight-safety/when-humans-fly-high-wha...