We purchased these for our 3 year old to enjoy the snow and go winter hiking in Missouri. So far, he has only been outside for a total of 1 hour (playing in the snow) to 1 hour and a half (hiking, 20 min was on foot, and the rest in the child carrier). The boots, worn with snow wool socks, kept his feet toasty and dry (but the snow wasn't very deep). I checked his feet after he was in the carrier, and his toes were a tiny bit cool, but nothing worrisome at all.