>>670740this needs to be stickied... or anyone who can write a better general concept of how bags work can make their own sticky
...continuned...
bag liners can be effective especially when lined properly and pasted against the walls of the bag and not tightly against you, but covering the bag from the outside is still much more effective than adding an internal layer
again i will remind you to always keep in mind how sleeping bags work by your body heating the main chamber of the bag, which is why you should dress lightly. good synthetic thermal underwear is enough. i prefer the base layers 1 and 2 of GEN3 ECWS cold weather issue underwear made by polartec, but many other alternatives exist.
and never buy down bags, they only serve one direct purpose and that is extreme cold weather expeditions (-20 and below + traveling for more than 5 days)
there is literally no other use for down besides this, and you can pretty much expect maybe 4-7 uses and they have to be within 3 or 4 years tops.
