We have been getting a lot of questions about our gloves being good for "Cold Weather", so we figured we'd pass along a little trick that we use ourselves.
The current glove we have for sale, "the Mug Glove", will not keep your hands warm on those really cold days (although we do have prototype cold weather gloves, we just won't be releasing them until next winter).
That said, here is a little trick we have used in the past that has helped combat the cold while still wearing your regular gloves and keeping your dexterity.
First thing you need are a pair of your regular long finger gloves, of course. Also you need to find a pair of latex, surgical gloves. Park Tool also make Nitrile gloves that you can find at your local bike shop. Your bike mechanic probably has a whole box on his work bench too, and if you are really nice, or buy them beer, I'm sure they'll just give you a pair you can test out. (We tend to keep a pair of these in our bag/vehicle at all times, in case you find yourself around a trail and the weather takes a turn for the worse.)
As you should be able to see where this is going now, you first put on the surgical/latex gloves as a base layer, followed by slipping your rubber protected hand into your full finger gloves.
Note that this technique stops the wind from cutting through your normally vented gloves and chilling your hands, which also means your hands will sweat more. We have used this technique in many 4+ hour rides on cold days and when you pull your gloves off, your hands do look like you have sat in the bath tub too long.
We have never experienced any performance issues with our hands being able to grab that frosty beverage post ride though, so we believe this technique to be fairly safe.