What Our Gearhead(R) Experts Are Saying: "I have high arches and used to get foot fatigue on big days. These insoles changed that. They've got solid arch support, and the merino keeps my feet warm even on icy lift rides."For high-arched feet, comfort in a ski or snowboard boot starts with support, and the BootDoc Thermo X insole delivers just that. Built to stabilize and cushion where it matters most, this winter-specific insole combines a structured high arch profile with a merino wool top for warmth and moisture control on the coldest days.