I can't tell from your post if you're 1) referring to the source of the original question, or 2) if you're referring to my response to some followup posts.

If it's 1), then that answer to your question is "the many, many accounts I've seen/read from survivors who say they were afraid to let themselves sleep, lest they die from cold".

If it's 2) the answer is: some of the posters above basically said that. Look at their posts. They advise not "believing" your own judgment about hypothermia because that judgment may be clouded by... hypothermia.

It's a chicken & egg argument. Myself and NightHiker are arguing against it.