I'm the guy who's waiting at the ski lift before it opens and I get kicked off the mountain at the end of the day. I never go in, I use this pack to eat lunch in the woods. This pack has good pockets, a dry area and it's easy to fill the hydration bag. It doesn't stick out all that far so it doesn't interfere with being on a chair all that much. The heater system, well.. it works and it doesn't. The heater element goes from the bag down to the mouthpiece and this never froze, even after 8 hours in 10 degrees. I was surprised by how long the batteries lasted too, over 4 eight hour days in 10-20 degrees. The problem is that while the tube is heated, the mouthpiece isn't. Even though this is stored in a pocket, it did freeze. Usually this was if I went 2-3 hours without drinking. Still, sticking the mouthpiece in an armpit for 5 minutes was enough to bring the warmer water through and melt the mouthpiece ice. Not perfect, but certainly much more useful than an uninsulated and unheated hydration pack!

Fogged up heavily on the lift at 28 degrees and snowing on the way to their first run. The worst part is that the Vaporator lens is immediately ruined if you wipe away inside fogging. So what do you do? Can't see thru fogging, can't see in the snowstorm, can't wipe 'em without ruining the "high tech" lens. Made for a terrible dangerous run. The wicking foam is rather weak in regard to padding, seems to wick in moisture just as easily as wicks out. These goggles are full of fancy crap that just doesn't work. FWIW, I was guided down the mountain by people in perfectly clear Giro goggles.