I picked up a pair of ski goggles for use on really cold days. Today was such an occasion, -24C, so I busted them out. They were great....for about 1 minute and 25 seconds. Then they fogged up, completely. I wear a balaclava, and my breath got into the goggles, and condensed, then froze on the cold lense. I can't see how this would not happen to any goggle design that I am familliar with. How do you guys keep your ski googles frost free?