Originally Posted by
~Reason~
I have a strong connection in my head between "fingers not working" and "danger, brain not right" . It has saved me several times. Good thing is, its a simple rule that works for hypoxia, hypothermia, narcosis etc. If you struggle with something like a buckle, keys or zipper, stop. ................
The few times with hypothermia I was also only keyed in by clumsy fingers, never by shivering nor feeling particularly cold or odd.
Trying to rapidly tap your thumb to your pinky is a good test. Don't depend on being aware enough to recognise it in yourself, but for me "fingers not working" has the best chance of penetrating a foggy brain.