Layering

OK.. just so you know that I am not making this stuff up.. and in an effort to always keep learning, here is a great article from Backpacker magazine's Web site :

In winter, your comfort–and even your life–depends on savvy layering. Here's how to dress for everything from sun to storms.
Start cool. "People often make the mistake of beginning a hike overdressed, and as a result, start to sweat profusely soon afterward," says Colorado Mountain Club instructor Gyorgy Kereszti. Adjust your layers so that you're cool–even shivering–when you start hiking. You'll warm up quickly as you move.
Avoid getting wet, either through sweat or precipitation. Moisture will chill you as soon as you stop moving, and introduce the possibility of hypothermia later on, when the water freezes. As soon as it starts to snow, put on a waterproof shell to keep other layers dry.
Try a windshirt. "Most days, I wear just a thin, wind-resistant baselayer," says NOLS's Marco Johnson. Key feature: The breathable fabric blocks chill gusts while letting moisture escape.
Pace yourself. When wind or icy temperatures prevent you from removing layers to cool down, hike slower to keep from overheating.
Opt for a breathable fleece or wool midlayer (when conditions permit) instead of a shell, which tends to trap more perspiration.
Wear gaiters, which keep crampons and ski edges from slicing your pants and provide additional waterproofing to keep your feet dry.
"Keep layers accessible," says Alaska Mountain Guides's Eli Fierer, who loads midlayers and jackets at the top of his pack, where he can grab them quickly.
Anticipate weather changes, and layer accordingly. Pull on a shell before emerging onto a windy ridge, and add on a fleece before you become critically cold.

Work first. In camp, complete sweat-inducing chores before bundling up in a down jacket. You'll give moist inner layers time to dry and avoid dampening fragile down.
Wear layers on your feet and hands, too. Use thick wool or synthetic socks and mitts over a thin, quick-drying liner.