Piece of cuben to boost warmth?

Its acting like a partial vbl … Similar to wearing a rain jacket to bed

If its cool enough for your metabolism you dont sweat much anyways

Its an old moutaineers trick to put your lower body in ur pack on cold bivies … It might save yr toes

;)

One of the things i plan on trying if we ever get some real cold around here (for me, that is 10 f and colder), is to try something like what you just talked about. A VBL loosely drapped on top of me in between myself and the insulation.

It's not an original idea, Doug (Idester) had mentioned it before, and he seems like a pretty smart and experienced guy. He said it allows some venting of moisture, but not directly in the quilt. (provided the VBL is larger than the quilt).

In your case, one of the things i would make sure, is not to wear the down jacket while doing this, but drape it on top of the cuben, or on top of your quilt, rather than wearing below it.

I would expect above 25, that even with some moisture venting, it might be a wee bit uncomfortable, but that is just a guess.

I've found that non-breathable layers trap a surprising amount of warmth. I really like bread bags over my feet in cold weather.

I wonder how many have shivered for a night having a paperback book next to them…
One of the hobos tricks is to stuff crumpled up paper between clothing..
Riders at the Tour De France still shove a newspaper under the jersey at the start of a steep mountain descent.
mind you you can also just open up one of those thin plastic shopping bags and put that in between your layers.(I use them for food/kitchen bits /rubbish and as foot warmers, like Justin..)
Not high tech nor expensive but it really does the same thing.

I would like to add that if I did not have that extra piece of cuben I would have had a very cold restless night.

It did seem to trap the heat that was rising up from my body and reflect it back into me. Great multi use piece of gear imho.

I understand the multi use aspect of using the Cuben, but what about a dedicated SOL emergency blanket used in the same manner for serious cold? It weighs 2.5 oz and is suppose to be tougher/more durable than the mylar kinds. Also only costs around 4 dollars. I would imagine that in serious cold it would really boost the temp of ones quilt.