Actually they are very light. I have several pairs. The bottom is like a foamy material (kind alike what flip flops are made out except just a tad thicker .. it's SOOOO comfy on your feet), so that's light. The outside if suede, so that's light, and the inside is wool, so that's light.
They don't make your feet sweat because they are lined with wool, which wicks away any hinf of moisture .. thus keeping it from building up and keeping your feet warm and dry at the same time (actually those 2 go hand in hand .. since your feet don't sweat in them they aren't wet/moist and thus don't get cold .. which is why your toes do get cold in regular boots).
The instructions you get when you buy a pair go so far as to tell you to not wear socks. Wool, being a natural fiber, is also a natual soil repellent, so they won't smell bad or get gross inside. If you wear socks .. your feet WILL sweat though; because the cotton socks on your feet, inside the wool, will make your feet sweat .. and then your feet will get COLD.
Also, to wear these in snow all one needs to do is apply a water repellent spray to the suede outside .. then you can tromp around in snow all day long.
The really furry ones though, are just for looks/novelty. I have some pink furry ones that are strickly house shoes.
see, even 10 yr olds like em :24::24:
:24:
