"downstairs" in the campervan it is 12c and not much more upstairs but just a normal duvet for us to sleep under...

"downstairs" in the campervan it is 12c and not much more upstairs but just a normal duvet for us to sleep under upstairs and a sleep bag + duvet downstairs for our little girl. We are all perfectly snug. Why do we burn so much gas at home? We should just live under duvets :-)