Pass out

[Rose of Madmen]

I'm gonna say this quick. 

If fatigue drops to 0, instead of losing health player looses consciousness.

Then you wake up when your fatigue reaches 5-15% 

If you were outside and fell on the snow you're probably dead, or half alive. 

If you were indoors you're probably fine, maybe a bit bruised because of the fall. 

What do you think about this idea? 

[Mroz4k]

Dont think it should be immediate. I had thought of something similar in the past. I think it should be similar to how intestinal parasites work. Once you reach exhausted, there will simply be a gradually bigger risk of passing out. That way, you can still move around for some time after you are exhausted, but the longer you are so exhausted, the higher chance of passing out. Lets say at 20% risk of passing out, one can actually pass out. There should be some margin of error, because the most of the time you run exhausted is mid rope-climb. 

Rest of this looks fine. I like the idea that would force people to keep their strenght up, not just carrying capacity issue and slow 1% degradation of condition. The risk of falling asleep for a bit in the middle of nowhere for a bit is a serious issue. Like you said - it could be in a middle of a strong push during bad weather outside... that could be very deadly.

All in all, a good idea, but would have to be balanced out. Simple flat out falling asleep as soon as you reach red would not be feasible for the game. But having it gradually creep up as a risk with intestinal parasites would make more sense in my opinion.