I just got a hammock sock from Hammock Engineer, similar to the one (from the plans?) at: http://www.tothewoods.net/HomemadeGearHammockSock.html
OMG! This thing is great, it weighs about 11 OZ but added at least (percieved) 5 Deg. warmth.
On the test night in question the temp only got down to 40, but there was (I think) significant wind chill. In my back yard the wind usually (90%) comes from the West, or at least a Westerly direction, for some reason it shifted to coming from the North that night. without the sock I would haveundoubtedly had to change orientation of my tarp / Hammock or go inside & sleep in a, dare I say it, , , Bed But with the sock on, I slept thru the night. H.E. has a draw string at the head end of the sock, & I had it pulled nearly closed, leaving about a 4" diam. opening, this was facing into the wind, yet I felt no breeze at all. I feel that with the tarp / hammock oriented correctly the added benifit would have been about 10 degrees or more. I woke several times without my overquilt on, granted I was chilly, but I wasnt overly cold, and warmed quickly once I re-covered. The night before under similar conditions (wind from the west tho) I would NOT have been out from under my quilt, so I must assume I got a bit too warm, which is GREAT!
I do'nt know if such a thing would work on a HH, but on a Spear style (I have a SG "Skeeter beeter" travel hammock) it is WONDERFUL. And an additional 5 - 10 or more degrees for only 11 OZ, It's worth the weight "cost", at least to me. AND, it fits inside my snakeskins.
So, if you have the ability, I highly reccomend a "hammock sock" at least for cool or cold weather.
SG "Skeeter beeter" travel hammock.
SG 9X9 "Neo" tarp
KAQ Patomic underquilt.
Very OLD (over 21 years) 30 degree sleeping bag, used as a quilt.
14" x 20" X 1/4" ensolite pad under my torso (it's my sit pad) just because.
With the above set up, I easily do 30 deg.
Add the "H.E. special" Hammock sock, and I think (hope?) I can get to 25, maybe lower.
Imagine how cold I'll be able to go with a new overquilt Which I order this afternoon.