Im new to hunting but a lifelong angler, including ice fishing. Ive had a lot of -20 (C) days of long sits on the ice and in my boat hunting muskies for 6,7 hours a day in freezing temps. Was out in zero degrees (celsius) the other day for half a day and my feet did not get cold. My boat is single console so no enclosure or heat. These boots are so warm I was almost too warm for the first 4 hours or so if thats even possible. By the end of around 6 hours my feet felt normal. Never cold. I just have never had boots like this before, and Ive gone through several including other Lacrosse models. These stand out/are exceptional. Super warm. Im a size 10 but ordered an 11 so I can have room to generate and retain heat and wiggle toes. Paired with a single layer of merino socks, these boots are unbeatable.