Even just putting two tents on top of each other already improves the insulation a lot, because of the air layer. This was used already during the second world

Even just putting two tents on top of each other already improves the insulation a lot, because of the air layer. This was used already during the second world war over here. In reality in general it's hard to do things that make sense as a whole - large organizations can only optimize invididual parts.