Most shoe or boot soles aren't insulated, reps at 3M told me at last year's Outdoor Retailer show, and can be a huge source of heat loss. 3M's thermal insoles aim to fix that.

A U.S. Air Force F-16 Fighting Falcon fighter aircraft assigned to the 18th Aggressor Squadron takes off from Eielson Air Force Base, Alaska, Oct. 6, 2014, during RED FLAG-Alaska 15-1. RF-A is a ...