It's been mentioned that bladders with drinking tubes can freeze. If you have one and get caught in the cold, empty the tube after each drink by blowing the water back into the bladder. It's not a cure all but it does help.
This also helps in hot weather as the water doesn't get hot in the tube.

“In a time of deceit telling the truth is a revolutionary act.”
― George Orwell

It's not over when you lose. It's over when you quit.