In fact, there is a very thin heat layer in close proximity to our skin that is fragile but very effective. A microclimate.

Our goal is to trap this radiated heat and use it as an insulator against the cold.

Wearing a breathable windblock layer close to the skin allows us to protect this microclimate. It's surprising how effective this is.

Dry clothes help conserve heat:
When preparing to set off in the cold, your biggest challenge will probably be to get underway before your underclothes become damp. If you're dressed for extended riding at 60mph in a temperature of 32-35f, you'll be way overdressed for walking around the bike for ten minutes as you finish taking care of those last-minute tasks. Be vigilant. If you notice that your underwear or inner layers are damp, you've blown it.

When this happens, I go back in and change into dry clothes or use the clothes dryer. It's a hassle, but it's that important. Damp clothing will not only cost you in terms of some evaporative cooling, but it is many times more conductive of heat than dry clothing. Not a good way to start a long, cold, ride.

Manage dampness:
After six or seven hours of cold weather riding, I usually do some humidity management. You'd be surprised how much dampness can accumulate in your clothes over time. When I stop for gas or food, I use the electric hand dryer to ventilate my jacket, under my fleece vest etc. Same for my gloves. This not only helps dry out excess humidity, it also recharges my inner atmosphere with warm, dry air. If I happen to pass a laundromat as I ride down main street in some small town, I'll throw in my jacket, fleece vest, and riding pants as well as anything else that I can. What comes back out after ten minutes makes a world of difference. The best ten minutes and fifty cents I can spend.

Note: In terms of cold weather riding use, cotton clothes are the worst performing. Though very comfortable when dry, they become a liability when wet. Investing in some good wicking underwear will serve you well for many years.

Bruno
Montreal, Canada