Pretty neat trick. Got to hand it to those Scandinavians.
Another trick I have seen that came from that part of the world was to make a stove out of a piece of firewood. They took a dry pine or spruce log common to that region, cut to 2-3 feet long, stuck it upright in the snow then split the top end with a chainsaw down 6-8 inches, sprinkled tinder (sawdust, shavings, paper, etc) down into the split and lit it. The tinder caught and the reflected heat from the 4 quarters allowed it to burn quickly. They put a coffeepot or kettle on top of the log and it heated the water/tea/coffee very effectively. They could do the same thing by splitting the firewood with an ax into quarters and tying them back together.