Hi Slunnie,
I agree with Numpty's Missus.
We don't only pass moisture with our breath, but through the pores of our skin.
Extreme eg.: Those doing overnight bushwalks often fit a packliner that in an emergency can be used as an emergency shelter. It is like a large garbage bag, but thicker & tougher.
One night I decided to test this. We slept under a rock shelter & I still used my sleeping bag.
In the morning, even though I had slept with my upper body outside the "shelter", my down sleeping bag was saturated. :o
As we were "walking out" that day it wasn't necessary to try to dry the bag. Otherwise hypothermia could have become an issue.
Bushwanderer

