Comment: Re:If you're going to crash (Score 1) 239
No emergency alarm, maybe, but anyone who's done aviation high altitude training should be able to detect half a dozen symptoms of hypoxia that they might have. Whether you'll detect them in time to do anything about it is another matter.
Mine included: racing pulse, tunnel vision, blue fingernails, inability to do simple maths problems. Some people get aggressive, some euphoric, some break out in a sweat.