I assume you mean the clothing. The motivation was partly due to the fact that the kid wanted to drive to school, partly due to my brother's comment once that he rode at 25 below, partly due to a new jacket I wanted to test, and mostly due to just wanting to see if I could do it.

Feet, inside out: Wool dress socks, cotton athletic socks, thick wool socks like for inside snow boots, waterproof insulated hiking boots from Payless Shoesource. My toes were getting just a bit cold at the end (6.3 miles). I might have stuffed in just a bit too much sock material for proper air space.

Legs, inside out: Cotton work pants (like Dockers, but not "Dockers"), heavy army surplus wool paratrooper pants with plastic wind shields sewn into the thighs. Legs were perfectly comfortable. (For those of you in Minneapolis, my pants were a gift many years ago, but I believe I saw some at some time in 2006 at American Surplus downtown on First Avenue North and Fourth Street.)

Torso, inside out: White cotton Tshirt, cotton button shirt (what I wear to work), heavy wool army surplus sweater, custom-made biking jacket of lime-green wind-blocking fleece. My brother made it for me for Christmas--one of a kind. The upper body felt just a bit cool until the end of the ride, with just a hint of perspiration. It reminded my of wearing a plastic bag for a glove--no wind gets in but it's cold anyway. However, I was not cool as in uncomfortable, and by the end of the 6.3 miles I wasn't cool at all. I think that I should replace that white Tshirt with some long-sleeve wicking underwear like skiers use. I think that would eliminate the feeling of perspiration and also add just a bit of warmth.

Head: A tube of fabric around the neck to seal up the neck of the jacket. A balaclava over the head. Ski goggles. Over the mouth and nose, a mask that covers the lower part of the face and fastens in back with velcro. I don't like the thing because it keeps slipping out of place, but it does cover the exposed skin. Finally, just in case, I put into the helmet a small rectangle of fleece just to slow heat loss through the top of the head. The head was generally fine, but there was just a tiny line of coldness somewhere near the top of the goggles, probably because there is a venting slit at the top, or possibly because the top edge of the goggles did not exactly meet the face opening of the balaclava. Nothing serious.

Hands, inside out: Hand-knitted wool mittens from my late aunt, hand-made fleece mitten liners, another hand-made liner of wind-blocking fleece, leather shells. Hands were fine except for the tips of the thumbs. I usually have to pull the thumbs in with the fingers a couple times on the trip to warm them up. I also stopped at the two-mile mark, at a grocery store, to straighten out the face mask, so the hands probably warmed up a bit there.

Last week we had a day of two degrees above, and I wore this outfit. I was nearly perfectly tuned; I lost heat as fast as I generated it and was neither hot nor cold, but just right.