Living in Florida I can't attest to their warmth and have only had them for about a month, enough time to wash all six pairs at least twice so can't comment on durability. Because they are cotton and long, they are not easy to put on and take off after two washes. I plan on giving them to GoodWill and am trying to find thick socks made out of stretchy synthetic material. I have a pair of thick wool socks that are easier to put on and take off. I want thick socks to prevent plantar fasciitis and that was a problem until I switched to thick socks.