use the stupid questions thread, idiot.
>>2519285>What are they?a plastic bag or something. a barrier that keeps vapors out. i use the plastic bags that loaves of bread come in.
>How do they relate to layering?they're a way to keep your feet dry. you usually layer it between a thin liner sock and your normal socks.
>When should they be employed?when you need to keep moisture out of your shoes. you need to pace yourself when using them in cold weather or else your feet will sweat.