"As the zombies are living dead their heat control won't most likely be working as well as that of a living human's. That would lead to sluggish moves and general slowness. Also, if they spent enough time in the cold weather they would become unable to move."
And if you are thinking what the h***, what's that based on, read a little bit of human biology... Anyways, that's what a couple of friends of mine and I came to when dicussing zombies one day. And if there's so snow, there's cold temperature. And Död Snö can do what ever it wishes (made me laugh, that movie)~
and can they catch a cold? As they are dead, they can't provide the right enviroment for cold viruses to live, eve though they could otherwise carry the virus. They can't have a immune system to speak of so actual cold symptoms would be pretty unlikely (you need the immunesystem fighting against the virus for that)...
But then again, my pet zombie says they can... *looks at the young girl next to him*