BMW 180 temperature

I cannot say empirically what an Arctic Spring would entail, but some of the conditions experienced by the Arctic 1000 team are posted.
http://www.ryanjordan.com/2006_arctic/2006/06/ultralight_shel.html
From the discussion on the above link it sounds as if the day’s high reached the 30s. Because the Arctic 1000 crew slept during the day, one can infer that the BMW 180 was used at this temperature. Of course, the quilt’s warmth was augmented by the additional clothing listed. Presumably there was minimal insulatory overkill, although I do not have any information from the trekkers (beyond the BPL and Arctic 1000 sites) as to how close to the thermal margins they were with this quilt. Note that Jordan states the quilt was also tested in Montana during the springtime which may also help to put the temperature range of the BMW 180 into perspective. Personally, it sounds like a very appealing item.

First, I believe quilts pose enough of a draft control issues that they are really only suitable for (a) warm temperatures where a little breeze really doesn't matter – e.g., summer on the AT, or (b) combined with puffy clothes on the top and bottom.

So, in that regard, I think the 180 + Cocoon puffy clothes (either a pullover + balaclava or hoody, and pants) will get "most" (>50%) of you down to freezing conditions.

The Arctic was damp in the river valleys, but not particularly cold. Our lows were somewhere in the 30-35 range.

I "felt" much colder on a recent trip into the Wyoming Desert and Wind River range, where we had temps down to 22-25, but I used the same system. By the third night, I slept very warm, my body had become accustomed to the cold temps. I was chilly on the first night, but not so much that I didn't get a reasonably night's sleep, and a lot of that was probably a result of a breeze going across my bag (I wasn't using a bivy) because I pitched my tarp high.

Ryan,

Can you tell me what size the Cocoon 180 stuffs down to?

Thanks,

Mike