I got home the other night from climbing, changed my clothes, and climbed into bed. My wife rolled over and said, "You're not going to shower? Gross!" I told her that I didn't sweat the whole time I was climbing and I'd showered before I left, so I didn't stink. She rolled over, smelled me, and agreed I didn't stink and said I could stay. She then said, "How do you go climbing for four hours and not sweat?"
The key is proper layering
A couple good link for more on winter layering:
If the weather is 25 degrees and not snowing:
and I'm hiking uphill, I wear a long sleeve baselayer (Arc Rho Ltw) and softshell pants.
If I'm climbing, I throw on a weather/wind resistant hard- or softshell to keep dripping waterfalls at bay. I really like the Arcteryx Acto MX Hoody or I use the Arcteryx Alpha SV Jacket.
If I'm resting I throw on the Atom Lt Hoody. I may layer the NWAlpine black spider light hoody under the atom is I think I'll be sitting around for a while.
If it's snowing, I throw a hardshell over all the layer (with all vents open if hiking)
If the weather is 15 degrees or colder and not snowing:
and I'm hiking uphill--Baselayer, NWA hoody (if not windy) or Arc Acto Hoody (if windy)
If I'm climbing--Baselayer, NWA Hoody, and Arc Acto Hoody or Hardshell (Arc Alpha) OR baselayer and Atom Lt Hoody. The Atom as a climbing layer is one of my favorite options.
Climbing in Atom Lt Hoody, Middle Teton, October 2010
never overheated, never got too cold
If I'm resting--Rab Neutrino or baselayer, NWA Hoody, Atom Lt Hoody, and hardshell.
If it's 15 degrees or colder and snowing:
and I'm hiking uphill--baselayer, light softshell (Arc Acto) or NWA Hoody (not water resistant, but if it's that cold you shouldn't get wet in it, unless you're really working up some steam).
If resting and snowing--same as if not snowing. At 15 degrees or colder, there is no need for waterproof. Even water-resistant is usually unnecessary. The snow simply won't melt, unless you sit or kneel in it.
I pretty much take the same jackets on almost every trip now. If the weather is going to be above 15 degrees but below freezing and I'll be moving most of the time, I take a baselayer, the Acto, and the Atom Lt Hoody. I wear the Atom to climb in if it's near 15, the Acto to climb in if it's closer to 25 or 30, or all three if I'm belaying.
If the weather is below 15 degrees, I take a baselayer, the NWA black spider light hoody, the Acto, and the Rab Neutrino. I only wear the Neutrino for belaying/sitting around, but I'm always warm.
Anyway, that is, in a nutshell, how I usually layer during the winter.
What works for me may not work for others at the same temperature. It varies based on many factors. Body fat percentage, diet, fitness level, hydration level, etc. The key is to understand the principles--hike slightly cool, action suit/belay layers, etc., and adjust them according you one's own personal physiology.
Some thoughts on particular pieces of gear that I have really been impressed with (or not) will be on Winter Layering Part 2