From Wade Davis, Discover magazine article and TED lecture

The Inuit didn’t fear the cold; they took advantage of it. During the
1950s the Canadian government forced the Inuit into settlements. A
family from Arctic Bay told me this fantastic story of their
grandfather who refused to go. The family, fearful for his life, took
away all of his tools and all of his implements, thinking that would
force him into the settlement. But instead, he just slipped out of an
igloo on a cold Arctic night, pulled down his caribou and sealskin
trousers, and defecated into his hand. As the feces began to freeze, he
shaped it into the form of an implement. And when the blade started to
take shape, he put a spray of saliva along the leading edge to sharpen
it. That’s when what they call the “shit knife” took form. He used it
to butcher a dog. Skinned the dog with it. Improvised a sled with the
dog’s rib cage, and then, using the skin, he harnessed up an adjacent
living dog. He put the shit knife in his belt and disappeared into the
night.