In the summer your feet will actually perspire more if you wear anything other than cotton next to your skin, especially polypro. Cotton when it soaks cools the foot, reducing the rate of perspiration. The foot only perspires coz it's warm, so cool it down the simplest way. The other point I'd like to make is having a pair of thin cottons under wools or any other thick sock is the damp cotton acts like a 2nd skin, moving with the foot, reducing the chance of blisters more than from any other technique. No sock sticks to the foot better than wet cotton. Of course, you understand I'm referring to warm weather. In the winter the rules change, that's where the polypro comes in.