For me, the biggest leap of faith is to take off layers when you are in your bag and still feeling cold. I used to have a good laugh when folk suggested using spare layers as a pillow. Spare layers? I didn’t have any. Now I have learned that, slightly counter-intuitively, taking my jacket off will warm my feet as heat can be redistributed throughout my sleeping bag. Of course, now I sleep with the love of my life: a custom-made PHD bag – brilliant.