I'm going to disagree with the "cotton kills" theory. Not to suggest people discard synthetics and go back to cotton, but to illustrate a concept I'll call "Living within the limitations of your gear."
I have to agree with that, and W_D...
The appropriatness of cotton depends on where you hike.
When I'm bushwhacking here through thick bramble, cotton denim jeans are the way to go, the heavier the better. But I wear my nylon zip-offs a lot too when backpacking. They're lighter, pack smaller, and work great with layers. I can wear thick fleece pajama bottoms under those, and long johns under the fleece, and stay pretty darn warm and comfy down into the teens.
Cotton does take a long time to dry. It can be almost impossible to dry. A few years ago I spent 5 days where it went from fog, to drizzle, to rain, and back the entire time and I never could dry out my cotton socks. I did manage to singe them, but not dry them.
Last winter I found out by accident that you can make a great clothes dryer with an emergency blanket. Either solar or a small campfire will power it. I haven't tried to prefect a method, but just rig the blanket into a small box and put your wet clothes in it and build a small fire in front of it. It works fast and it won't singe your socks