The Comfort of Wool

Cold weather has arrived a bit early this year, so I've had to break open the tubs of warm clothing before Thanksgiving. Most years I can get by working outside in November wearing insulated underwear under my jeans and a few more layers on the top half of my body, but not this year. Snow on the ground before Halloween isn't a good sign around here, we're in for a long winter.

I realize that some of you are laughing at me right now, since you live in areas that rarely see snow or temps below 40°F. That's fine; laugh all you want as you're slapping mosquitoes in December. I've lived in a lot of different climates, and know that even in the desert it get cold at night, so I try to plan ahead for cold weather or having to live without heat. The camping trips and other overnight stays in the great outdoors have instilled in me a sense of appreciation for warm clothes. If you ever travel at night in the winter, you should at least have warm clothes in your vehicle bag.

There is an old saying about winter clothing: “cotton kills.” It's based on the fact that cotton loses its insulating value if it gets wet. Sweating in cotton long-johns is a good way to learn about hypothermia, so it's best to avoid either sweating or cotton. Most of my insulated underwear is cotton, but I have learned how to adjust my clothing to avoid sweating in it.

The whole concept of dressing in layers is designed to allow you to remove clothes as you start to warm up, and it's always better to be a bit chilly than to start sweating in winter. The sweet spot is between shivering and sweating, and it varies from person to person. I'm one of the people with single-digit body fat so I don't have a lot of natural insulation, I have to buy my warmth instead.

• Silk is a fair insulator, and I do own a few undershirts and socks made of it. Pleasant on the skin, but expensive and very touchy to wash/dry. Silk socks don't work very well in boots because they're too “slick” and tend to slide around my feet as I walk. Since I don't want to deal with the hassles of wearing garters, I avoid silk socks now.
• Modern fibers like polypropylene (PP) don't absorb moisture and will retain more of their insulating value than cotton when wet, but they aren't as comfortable to wear as a natural fiber. I have PP long-johns, but they're stiff fibers and tend to be more irritating to the skin than natural fibers. 
• Polyester (PE) is one to avoid, since it doesn't “breathe” very well and will trap moisture next to your skin, making you feel clammy and cold.
• Nylon is a tricky one. There are so many different ways to spin nylon into a yarn that it's hard to know how it's going to treat your feet. Basic nylon dress socks are horrible; they don't breathe worth a darn and will trap moisture inside your footwear. Some of the “fluffier” nylon yarns that I've seen fall between the PE and PP fibers for insulation value.
• For basic winter socks, I prefer wool. I've had wool socks last for up to four years of daily wear when properly cared for (the Army used to issue only wool socks, and I wish I had a good source for them now). They're expensive and need to be washed with care, but they breathe enough to allow sweat out and will retain their insulating value even when wet. I've inadvertently tested this several times over the years, by having a foot break through a thin layer of ice and ending up knee-deep in water. You extract your foot, pour the water out of your boot, wring out your socks, and put them back on. While not exactly pleasant, a wet wool sock will keep your foot warm. Cotton and cheap plastic socks need to be dried before putting them back on or you'll lose more heat from your feet than if you went without socks. Wool also has the advantage of being a lot easier to dry with unconventional heat sources; plastic fibers are prone to melting before they get dry near a campfire, while wool and cotton will be completely dry before they start to burn.

This post came about because I haven't had time to do much laundry lately and I ran out of wool socks, so I dug down to the bottom of my cold-weather tubs and found some “insulated” socks that were received as a gift a few years ago. They were cheap and mostly polyester, so while they were abundantly thick and warm for a few hours, by noon I had to change them out because they were wet from the moisture they had trapped inside my boots. The 16 hour days meant that I had to change socks twice during the day and that just meant more laundry to do when I got home. I think those socks are going to be relegated to the rag bin when they come out of the dryer.