I got a bargain price reindeer skin the other week, and it got me to wondering about making reindeer skin clothes, its not something Im actually likely to do, but looking at all the far northern peoples clothing, they all seem to wear the fur with the hair on the outside when surely it feels warmer on the inside,a s Id assume warm air is trapped closer to the skin. Im sure they are obviously right and Ill be wrong for some reason, but is it more to do with waterproofing reasons or allowing sweat to escape? in which case, if a person were to make a sleeping bag or just a night jacket out of reindeer fur for a cold night in a temperate climate where their life didnt depend on it, would it be warmer and more convient to put the hair on the inside?