I’m on a budget, and will eventually make a simple quilt to use in the warmer months.  I’ll most likely just use the 3.7 Combat shelled in 1.1 ripstop.  I had thought that maybe I should just go ahead and make two of them, since I often go on canoe trips with a friend in the summers.  Although it would be heavier and bulkier to carry, I wonder what kind of temp rating two of these quilts would have combined?

Two layers of 3.7oz XP Combat yield 5.8 clo.  Maybe the bit of air gap between the two will add a little but let’s be conservative and ignore that.

I’ve slept under quilts quite a bit have not been “fortunate” enough to get very many of the right nights to test their limits.  But the data points I do have suggest that I start to feel cool below 30*F under a quilt providing 5 clo. (6oz PL1)

Just this morning I woke up comfortably at 9*F wearing light wool socks, nylon pants, long sleeve cotton shirt and an unlined nylon hoody under a pair of quilts that totaled 7 clo.  I was under a 5x8 tarp in a silnylon/momentum bivy that was not zipped closed.  That was OK but not toasty enough to make me think I’ll be able to push that to 0*F (but I’ll likely try :-) )

Limiting air infiltration around the edges is a key factor when pushing low temps with quilts.  Approaches I’ve seen or tried are:

* making the quilt wide enough to be easy to keep tucked underneath you (weight penalty)
* tying it with fabric straps under you (fiddle factor penalty, especially if you toss and turn)
* attaching quilt edges to your pad (fiddle factor penalty and still leaks some unless it is continuous attachment ... zippers are heavy and velcro pulls loose easily, also unless you use a narrow pad, the pad holds the quilt away from your body)
* use a single layer fabric bottom (sleeping bag with no insulation underneath) (I have not tried this)
* making a shaped quilt sized to the user. (I’ve been pretty happy with that)

Lastly, different people have different furnaces ... so my experiences may not match your’s.