Mid 40's Sleep System

[JustDSM]

Wanted to get some takes on something I'm thinking about trying to keep bulk and weight as low as possible. I'd like to hear from those who've tried similar or have some setup you think would meet the intent of what I'm trying out here.

I'll be heading out for a weekend backpacking trip to a NF area here in the SW part of New Mexico where the temps are forcasted to be in the low 80s for the High and the mid 40's in the evenings. No rain is expected. We're packing in a few miles to visit a natural hot springs and I'd like to test out a means to keep weight and bulk out of my pack (trying to fit everything in my CamelBak Fourteener).

The plan:
REI Minimalist Bivy
Thermarest NeoAir
Cocoon Silk or Cotton liner
Sleeping in my clothing

Does this sounds retarded? :-? I have no experience using this Bivy, as I just picked it up with my REI dividend and 20% off coupon. I gather it'll add some warmth, and I'm a "typical" sleeper as in not hot or cold, but I still like to be cozy. The only other sleeping bag I've got is a 20g Kelty down bag which is overkill as far as temps go, so I'm wanting to try and go as minimalist as possible still maintaining a acceptable level of comfort.

Is this feaseable? Better ideas? I'd like to see the looks on the other guys I'm going with when they see my daypack is all I'm bringing on a weekend trip! :eek:

[Tom Murphy]

I have tried something similar to this but ended up cold. I bought mid-weight wool baselayers/hat/gloves and a down vest.

Ended up having to break out my emergency space blanket. The blanket was a big help but also trapped moisture. Since I was only out for two nights I thought it was a good one time solution.

This summer I am planning on using a down quilt instead.

Also the REI bivy may work well in a dry climate, but it was a huge failure for me in New England. If I bought bivy again, it would be for winter use only and be eVent fabric.

[Kerosene]

There's no way that you'll be warm enough in this setup, even below 55F I'd venture, unless you're wearing insulated pants, jacket and socks to bed. I base my opinion on trying to sleep in a hammock with a 20F sleeping bag atop a pad. Once the temperature dropped below 60F, every time the bag pushed against the side of the hammock not insulated by the pad I would wake up with a cold spot. I think you'd be better off with a 35F bag (WM UltraLite is 16 oz) and a small tarp (8-15 oz depending on material). I it does rain, then you're not going to be very comfortable in a bivy exposed to the downpour.

[JustDSM]

Thanks to you both for your replies.

For clothing I'm going to be wearing a lightweight synthetic T, and some convertable Columbia pants (Silver Ridge I think?)

For packed clothing, I'll have a set of Patagonia Cap 3, and a set of R1 top and bottom w/ a fleece beanie. I'll also have my Marmot Super Mica but will likely only pull that out if I need to cover the mesh opening in my bivy.


I have tried something similar to this but ended up cold. I bought mid-weight wool baselayers/hat/gloves and a down vest.

Ended up having to break out my emergency space blanket. The blanket was a big help but also trapped moisture. Since I was only out for two nights I thought it was a good one time solution.

This summer I am planning on using a down quilt instead.

Also the REI bivy may work well in a dry climate, but it was a huge failure for me in New England. If I bought bivy again, it would be for winter use only and be eVent fabric.

I am starting to get the feeling I'll be a little chilly with this setup as well. I have some puffy jackets I could bring that pack pretty small, but I'd have to step up to my 38L Osprey Kestrel to pack them, and then I'd have room for my sleeping bag making this a non-issue.. I might end up playing it safe and just bringing the bag and the larger pack for this outing and testing my theorized setup in the back yard sometime so I can always pack up and go home a "little" easier ;)

I too am counting on the low humidity and dry conditions here in the SW to fair better with the REI bivy. I've heard the reviews and figured I'd give it a shot since I picked it up with my dividend on discount. It'll be my first bivy so we'll see how I like it..


There's no way that you'll be warm enough in this setup, even below 55F I'd venture, unless you're wearing insulated pants, jacket and socks to bed. I base my opinion on trying to sleep in a hammock with a 20F sleeping bag atop a pad. Once the temperature dropped below 60F, every time the bag pushed against the side of the hammock not insulated by the pad I would wake up with a cold spot. I think you'd be better off with a 35F bag (WM UltraLite is 16 oz) and a small tarp (8-15 oz depending on material). I it does rain, then you're not going to be very comfortable in a bivy exposed to the downpour.

Now, this is a good point of reference for me, because I've hammock camped with a 20deg bag in the low 30's (maybe even dipping to high 20's) with a military poncho liner draped over. I used a ZLite SOL (2.6R) pad and was wearing Patagonia Cap 3 base layers w/ Smartwool Expedition socks and a generic fleece beanie. I was a little chilly but comfortable and able to sleep. Toes were the biggest problem, as they got chilled more than anything else.

I want to buy a WM MegaLite (I've got broad shoulders) But I was hoping to put off the purchase a little while.. I suppose if I had too, I could get it and have it for this weekend, but if I could get away with trying something a little different I think I'd enjoy learning about my gear and it's limitations..

Thanks for all the input thus far! I will give this some further thought and hopefully we'll get some more input to stir the pot. Thanks guys/gals!