Curtains reduce draughts and stop heat escaping by radiation. Not all curtains are equally as effective - just like winter clothing, adding a lining makes all the difference. You can buy thermal curtains and blinds, but keep an eye out at the Aberfeldy Thrift Shop, Remake in Crieff and other charity shops; they often have thick lined curtains available.

This document has ideas for how you can make a curtain insulate your home better. If you are handy with a sewing machine you  might try some of these ideas yourself.