Wool is your best bet. The gloves with the mitten flap are likely the warmest. I've tried the thick water proof leather gloves, snow mobile mitts, sheepwool lined leather mitts and have found these combo gloves to be the best. I have found that leather and nylon, once cold, will radiate that cold to the skin. Would you believe my heavy wool sweater is wamer than my -40 rated jacket with it's high percentage nylon outer layer. Even with an inner jacket I feel the cold radaite inward so stick to wool, it's still the best.