I have done a fair amount of experimenting with vapor barriers in a clothing system so far this season. I slept out last night and it was 4 degrees Fahrenheit. I used produce bags for next to skin vapor barrier liners, then smartwool mountaineer socks over them and then Feathered Friends down booties in my sleeping bag. My feet were borderline too warm. However, I found that the produce bags were super comfy and did a great job keeping my socks dry and warm. Why are liners recommended under vapor barrier socks? Is it strictly a comfort thing or is there something I am missing?
