Yeah,yeah, Cotton Kills,blah,blah,blah.....
Yes they are right, However..... I have worn cotton jeans while hunting for years!!! and I'm not dead yet!!!!! But, Cotton will never be as warm as wool when you are wet!!!!! Wool will also keep you warmer than ANY of the synthetics out there!!!!!
However,wool is also very hard to clean and dry when you are in hunting camp. When wool is wet,it must be hung to air dry. Many times over the years I have pulled on my wet wool pants that got soaked from the day before..... If you have axcess to a dryer either in camp or at home,it's nice to be able to throw your clothes in the dryer while your eating lunch and put on nice dry clothes to hunt that afternoon.Something you absolutely CANNOT do with wool!!!!!
As for thinsulate..... I have a pair of thinsulate lined camo jeans that are as warm(when dry)and quiet as any of my wool pants are.