Anyone played battlefield bad company 2 campaign? (I think it was that). There was a freezing wind up in a mountain where the screen would turn into ice and if it was totally iced you'd die. A similar system could work in Skyrim, when you jump into freezing water/walk in extremely cold areas without fur clothes your screen could start turning into ice, to warm you it s extremely cold. At first it wouldn't damage you, but soon it'd start doing it. Also, in a way that doesn't let you walk around casting heal spells in ice cold areas either.
Well fur clothes will not protect from freezing in water, making water do some damage isn't hard even in Oblivion ( Magma in oblivion just water with some settings tweaks) about other yes thats will be great, screen decals was confirmed so adding such freezing to screen will nice FX as well for Ice spells, also devs say wind will be more important so maybe ice cold wind will be also available, also cold resistance will have more importance in game as well as Nords will be more unique as available race.
I use Duke Patricks Basic Hypothermia II in Oblivion it's really immersive mod
http://www.tesnexus.com/downloads/file.php?id=32752
I remember that part. I get so pissed when im trying to gei in a house when the russians (Who is not effected by it) shoots at me....
Be are Russian give some advantages as you can see, also who need RadAway when better drink some Vodka instead?