My low was -2 F at the Frozen Cheesehead hang last year. I spent a miserable, cold night and learned a lot from the experience.
I then spent another night about a month later at -2 F, where I was comfortable and toasty warm. The difference? I went from a tarp to a canvas hammock sock. I also took a synthetic bag and I cut a hole in the footbox that I threaded my hammock through. Inside the bag I put a Reflectix pad with side wings, something missing on the earlier hang where the sides of my shoulders got cold.Down quilt under me and over me. Down hood with fur ruff and wool vest, with down pants and down booties. What a difference the micro climate in the hammock sock makes.
Some photos here: http://www.hammockforums.net/forum/s...025#post676025