My hubby works as an aviation mechanic and is out in all weathers year round. He also has some health issues that affect his circulation in his hands and feet. So it's very important to protect him from the cold. These socks have done a fabulous job of doing just that. He no longer complains of cold feet, even after a 10 hour shift. It's important to note that these socks keep him warm, but don't make his feet sweat uncomfortably. Will be buying some for myself as winter deepens.