The Kamik Luke EZ boot lines the interior with fleece and faux-shearling, wrapping little feet in real warmth through long stretches outside. Rated to -40degF, the boot pairs that lining with a synthetic rubber shell built to handle the kind of cold that goes well past an average winter day. A hook-and-loop closure with a bungee pull still makes getting the boot on simple, even for a kid who isn't ready to manage laces or zippers alone yet. What Our Gearhead(R) Experts Are Saying:"My little one stayed warm through a whole afternoon of sledding in genuinely brutal cold, and their feet were still toasty by the time we got back inside. That's the kind of warmth I actually trust for temperatures this extreme."