Originally Posted by
Cubdriver
How long does the average person have at FL250 before serious hypoxia sets in? If you use a supplementary 02 systems it can be hard to know what you are getting through the pipe/cannula. No low pressure warnings, it just runs out at some point.
Cub:
In the USAF chamber, you go masks-off at 25,000 until "you notice your personal hypoxia symptoms."
You are given some menial mental tasks, such as a puzzle, or a quiz with math problems.
Most people get noticeably stupid within 3-4 minutes. However, not everyone will put their masks back on. I didn't, the first time I was there.
I now know that in my symptoms, my face gets flushed and warm....just like when I drink (but I'm a happy drunk).
Useful consciousness at 30k is about one minute. At 40k, it is about 15 seconds.