COLD WEATHER WARMTH PERFORMANCE Dial up the comfort, warmth and control this season with dual thermal layers and a biomechanical shape that can help stabilize a man's foot for better edge control on runs. A GOOD, SNUG FIT Superfeet started making custom insoles for ski boots in the mid 70s. The REDhot is a direct result of those years of experience. With these insoles you get a snug, stable fit with less shifting and fewer pressure points or hot spots. Superfeet REDhot insoles are vegan and free of latex, nickel sulfate, formaldehyde and preservatives.