Keeping Warm
Cold or Warm
The choice is yours
"NO Cotton"
Yea,  When cotton gets wet it stays wet.  I
have  polyproproline, silk,  and wool. All
which will wick away any body moisture
and keep you warm.
"Vapor Barriers"
"Cold Hands, Cold feet,
Wear a Hat"
Dress in Layers.  Layers will provide at least two things.
1)  Layers cause air space which can heat up
2)  Allows you to dress to your comfort level.  Put on or
take off those layers as the temperature lowers or rises.  
Keeping air from getting to your skin will
make that area very very warm.  I'll use
vapor barrier socks when I'm camping.  I'll
have a thin pair of socks, probably silk or
even used nylon dress socks, then a vapor
barrier sock, and a wool sock over that.  My
feet have never been cold.

You will need to change the under layer
when you feel they are to wet.

A trash bag over our torso will make you
instantly warm.  Maybe a tee shirt 1st, then
the bag, Another layer over that and you
won't need much more.

The jury is out on this idea.  Over the years
I've been using vapor barrier socks all day
long.  Now, when I go out on hikes I remove
them.  They always seem to bunch up
during the hike and really contain a lot of
moisture.  I just make sure I change my
socks after the hike to keep my feet dry.
You loose 50% of your heat from your head.  Put a Hat on.  
Wool is great but itchy.  I'll sometimes have a bandana
"Stay off the Ground"
Simple advice,  But some people just don't think.

A reflector bubble pad or a closed cell pad to keep you from
the snow will make a major difference.  Use this while sitting
or sleeping.  When you get up to go to your tent or just to
clear your head, put something on the pad, Your canteen,
small log, Bottle of Yukon Jack, to keep the wind from
blowing your pad away.

Snowshoes make a great backrest
A tip around the fire
The reflective side of a space blanket will reflect
the heat right back to you