Most may already know this, but carrying a silk inner for your sleeping bag (available from any camping place) makes it easy to use your exisiting sleeping bag in much colder temperatures rather than having to decide to take a light weight sleeping bag or a heavier one just in case. I usually use a sleeping rated at -5c (well it was when new) and leave it open in the warmer months. One night it seemed cold enough so I tried out the silk inner. It got way too hot so had to remove the inner. The inner takes up bugger all space. feels nice when you get in it too
