5. WEAR ALL YOUR CLOTHES INSIDE YOUR SLEEPING BAG
If you want to avoid a heated argument with your new friends on your winter hike, whether or not to wear clothes in your sleeping bag is the number one discussion to avoid. A lot of amateur hikers as well as experts claim wearing clothes while sleeping prevents the sleeping bag from doing its work - the justification sometimes being as absurd as your body heat staying trapped in your clothes and making the sleeping bag cold.
False.
This is how it works - your body is warmer than the surrounding air, inside or outside your sleeping bag or tent. When a warm object comes in contact with a colder object, it loses heat till both the objects are at the same temperature.
The layer of air just next to your body, thus, is warmer than the air outside your tent. Every layer you wear traps some amount of this air close to your body. Your sleeping bag does the same thing. It captures warm air, that’s been warmed up because it was close to your warm body. It doesn’t ‘capture heat’, as that would be impossible to do and too much to expect from a bag of fabric and feather.
What you should be careful of, however, is not to wear so many layers that you start sweating during the night. This will make you cold again. Wear fabrics like wool and fleece that trap air and insulate you even when they get wet. But please, don’t sleep naked in your sleeping bag.
6. MAKE YOUR SLEEPING BAG WARMER
The only thing that makes your sleeping bag cold is dead spots - gaps between your body and the sleeping bag.
If your sleeping bag is too big, fill up the bottom with spare clothes.
Use a sleeping bag liner to add additional warmth to your sleeping bag. My favourite liner is the Seatosummit Thermolite - it adds 8°C worth of warmth to any sleeping bag, and the texture feels a lot better while sleeping than they synthetic fabric most sleeping bags use.