I saw that we had an interesting thread on Shug's courageous -40ºF night in a hammock, and since the Northeast is getting it's own cold snap, I thought I'd do some of my own testing and let you guys know how it went.
I believe underquilts are too heavy and not worth the carry weight in a hammock setup. I choose instead to use a sleeping pad in my hammock, and I'll detail my setup here.
Temperatures: -6ºF to -16ºF with a slight breeze
Hammock Setup:
Grand Trunk Ultralight Hammock (usually a Grand Trunk Nano 7, but it ripped…)
Thermarest X-Therm Torso Length Air Pad
Thermarest Z-Lite Foam Pad
Mountain Hardwear Ultralamina 45º inside of a Mountain Hardwear Ultralamina 15º
that's it!
Worn Clothing:
Darn Tough Merino Wool Socks
Baffin Insulated Slippers
Ibex Lightweight Merino Wool Baselayer, top and bottoms
Smartwool Midweight bottoms
Ibex Midweight Zephyr Zip Top
Patagonia Micro-D Fleece
Uniqlo Down Jacket
Arcteryx Atom SV Insulated Jacket
L.L. Bean Polartec Gloves
How'd my night go?
I slept like a baby both nights, and I slept at least 6 hours in a row. Since the human body has a ~2.5 sleep cycle, I estimate I was getting two complete cycles, waking up around 6-7AM being cold, and then falling back asleep anyways to grab one more sleep cycle before getting up at 9AM (I'm up late working).
Because I'm always cold in the morning, this system does let me wake up with the sun at dawn when I'm bike touring and backpacking, something I don't mind. I have a good enough understanding of my sleep system after this many nights to choose my insulating layers based on the temperature.
When it was -6º, I did not use the Polartec gloves, Uniqlo jacket, or Micro-D fleece. I added these for the -16º night.
Draftiness was a non-issue since the wind wasn't high, but on a windy night I have, in the past, added a tyvek sheet to line the hammock, which provides a bit of windproofing and protection against convective heat loss.
There was some frost buildup on the outside of my sleeping bag, especially around the opening for my face. This was expected and I imagine if I had a tarp over me, it would have collected the condensation and prevented riming on the bag.
My coldest area was my legs, since I can't afford insulated pants. Someday…
I'd be happy to discuss any details about my setup or about adjusting to cold weather through metabolism, since I've been honing my ability to sleep while cold for two winters now.
