BA Encampment

I was using a BA encampment recently, it was rated to 15 degrees and I was sleeping in an area that was at high altitude and got down to 36 degrees at night, I barely slept that night because i was chilled to the bone the whole night. I was sleeping in a t-shirt and shorts, I think this may be the main reason I was so cold, but I was also suspicious that perhaps it is the design of the BA bag, there is no insulation on the bottom which is designed to have a pad inserted into it. I had a insulated Air Core mattress in the sleeve that night, can anyone tell me from experience why it was such a cold night for me?

Did you eat and drink before bed? Were you cold before you got into the bag? I'm not familiar with that bag - did you have your head covered at night? Was there wind blowing through? Were you more cold on top or on bottom?

The clothes shouldn't make that much difference with a bag that's warm enough for the expected temps. But the pad has to work for that range. I've heard the IAC is not the best pad in colder temps. But there are a number of reasons you might have been cold, and probably it was several things combined - maybe the bag isn't warm enough for you, the pad isn't quite warm enough, and you were slightly dehydrated?

In those temps I couldn't have gotten undressed down to shirt and shorts without catching a chill, just in those minutes between changing and climbing in the bag.

I didnt have anything to eat right before bed, had a can of soup and a muffin for dinner, there isnt any sort of wind problem in my tent, I use a REI Arete 2 I didnt have the hood all the way cinched down, now that i think of it that was most likely what was wrong with it. I was thinking that the lack of insulation on the bottom was the main problem...

Obviously the warmth is different for everybody, but as a general overview a +15 degree bag with an insulated aircore pad, which has an R-Value of 4.1 should provide plenty of warmth into the low-mid 20s with very little clothing. Again, personally speaking, I would be almost on the warm side in temps above freezing with that system.

This leads me to believe that it was more to do with your food and hydration intake throughout the day. Soup and a muffin is not very calorie dense, and I suspect that may have been the problem.

The other thing that comes to mind is that perhaps your pad was not blown up sufficiently or leaked air during the night?

A couple of other points, I have no experience with this bag, but I know that a few BA bags run a little wide-- is this bag too big for you? If so then there may be too much air in the bag for your body to heat.

no im a big guy. I got a large bag im 6'2, 215 my feet touch the ends of this bag. Ill try it again, eat something calorie dense right before bed and make sure the pad is inflated the whole way and keep the hood up and tight to my chest.

I really think the hood is the main problem. Covering your neck ahd head are crucial for staying warm when you feel cold.

I'm suprised that you didn't automatically cover your head when you were cold. I suggest taking a light stretch polyester balaclave not only for sleeping but for cold mornings. It's another "dual use" item.

Eric

Here's another thought, triggered by you mentioning that you're a big guy whose feet touch the end of the bag.

Could the bag be too small? If your feet press against the foot of the bag, or your chest and shoulders are broad enought that they just barely allow the zipper to close, you'll be pressing the bag lining against the outer shell of the bag. This will compress the fill, eliminating its insulating value.

This is one of the things you have to be careful with when relying on clothing to extend the range of a bag: too much clothing will have the same effect of compressing the insulation.

Kind of makes a fellow feel like Goldilocks: this bag is too big, this bag is too small - if only I could find the one that was just right!

Bag compression is (I think) often enough the culprit, however in this case I would think more along these lines:
"Soup and a muffin is not very calorie dense, and I suspect that may have been the problem"
An easy way to increase your calories intake there is to add olive oil and or full cream milk powder.
When I was over there I tried the Nido. That was pretty good stuff.
Franco
BTW, I am with the "get a slightly bigger bag than your size" brigade. At 5'7" I use the 6' versions (or a quilt)

Well i dont know how much bigger bags come. I have a large size bag? do they come in lengths designed for different heights at BA?

All (or at least the majority) manufactures of sleeping bags offer their products in at least two length sizes-- regular (good for those who are 5'9) and long (6ft and above).

BA is one of the few companies that offer some of their bags for those who need a larger width size. Just looking at the Encampment-- the specs are 70/66 (shoulder/hip girth).

In my case, my optimal dimensions are a long bag, with 60" shoulder girth and a 56" hip girth, thus if I got the Encampment, it would be far too big for me, leaving me with too much dead air for my body to warm-- which would make me cold.

In short, width is just as important as length.