As DM, I once killed a PC with a blizzard. Despite multiple warnings about the severe conditions outside, the player had his character leave the safety of a cave and got dropped by the cold damage. We talked about it afterwards, and it turned out that he just didn't believe I was serious about using the weather rules.
Ditto. There are players that just don't understand that the environment can be as dangerous as the monsters.
Likewise, almost killing somebody with modifiers for trying to climb down a cliff in the sleet and freezing rain. He fell, dropped into the negatives, but still survived. The rest of the party found a narrow path down, and
still needed to roll. Then they had to fight wreckers.... At the end of it, they used sail cloth to make a shelter, and did
not try to climb back up. (Though, if I recall properly, gong down is more dangerous than going up....)
I'm from New England - and know that Mother Nature doesn't play around when it comes to cold. Both my girlfriend and I have done winter camping, though she had the extra special fun of doing it in the mountains of Vermont, near Sterling College, it was required for one of her courses there. I like winter camping, she, most emphatically, does
not.
The Auld Grump