These socks are great! Merion wool is the way to go to keep your feet warm. The "heating element" is under the joints where you toes enter your foot. The element is a little bit noticeable, but not distracting or annoying. I am going to wear these while fishing on Great Bear Lake in the North West Territory. The water temperature is about 33 degrees F. I'm confident my feet will stay warm as we troll in an aluminum boat for monster lake trout.these socks are wonderful , set on low and your feet are warm and dry love them. best if worn with lite merino liners to wick away moisture.