I wear them for hiking and mountaineering with mountaineering boots all year round except for winter when I wear thermal socks. They truly allow the foot to breathe and hardly sweat at all. They are extremely durable and tightly woven, with reinforcement on the heels and front part. They must be one of the few socks on the market where one is for the right foot and the other for the left (like gloves that fit separately on each hand). An older pair of mountaineering socks from another brand that I bought years ago at half the price of these has now developed holes, frayed, and become useless, while this Meindl one seems to hold up well over time. Of course, how you treat them also plays a role: washing with cold water (or at most 30 degrees), without fabric softener, and very gentle squeezing, and of course NO drying in a dryer or in the sun. This way, you will always have them looking like new.