My current sleep system is an EMS Mountain Light bag and a BA Insulated Air Core pad. Both are rated to 15-20 Fahrenheit but I find them uncomfortable below about 35° if there's wind. Typically I'll feel cold against the pad, though my top side is warm.

Last week I was about to head out for a 2-night trip. Forecast was blustery with low 30s at night, so I needed more insulation.

I could have picked up a blue CCF pad at Wal-Mart, but I had a roll of 18" wide Reflectix left over from making a pot cozy. I cut off 6 feet of the stuff to make a very packable 6.3 ounce pad.

Unrolled inside the sleeping bag, the Reflectix pad makes a significant difference. The first night out, it got down to 28°. Against the Reflectix, I was still toasty, even though my top side was cold. Throughout the night, I slowly rotisseried myself to keep warm enough. This pad turned what would've been a poor night of sleep into an acceptable one.

The second night, it was nearly as cold, but I decided to experiment with a trash compactor bag (2.3 oz.), which I use as my sleeping bag stuff sack, as a vapor barrier liner for my feet and legs. Again, this made a significant difference. My lower half was super toasty, albeit a bit clammy. I slept soundly and woke up warm.

For under $10 of materials and an additional 6.3 ounces carried, I probably added 10 degrees of comfort to my sleep system. I encourage anyone else to try the same!

Edited by hope_for_gorilla on 04/09/2012 21:50:06 MDT.

Did you use the Reflectix in addition to your Air Core pad?

thats funny, I had the same thought last night to use reflectix as a secondary R-value upper for the snow. I read a few threads and most people thought it wouldn't do much as a secondary pad but putting it directly against you INSIDE the bag makes a little more sense.

was it comfortable against the skin? doens't seem like it would be..

Yes, I was using both the Insulated Air Core and Reflectix pad. I was wearing a wool baselayer, so it was plenty comfortable. In the temperatures that you need one, you're probably not sleeping in bare skin anyway.

Sounds like you'd be better served by a warmer bag. Warmer, packs smaller, *and* lighter.

I experimented bunches with reflectix and a BA insulated air core pad before a long winter trip. With the right bag, I couldn't tell a difference, even at 20, 30, and 50 below. If I tried to skimp on the bag to save an ounce or two, I'd *need* to resort to the reflectix, but it was never as comfy as just using the right bag to start.

YMMV, obviously.

Do you think you'd get the same heat-reflective effect by just wrapping up in a Mylar emergency blanket? Edit: Wrapping up inside the Mylar, inside your sleeping bag.

Yes, there'd be no insulation value from the Mylar, but it seems like mostly the reflective properties you're after.

Much lighter of course.

Edited by ctwnwood on 04/17/2012 08:42:12 MDT.

I like it: the reflectix INSIDE the bag. Smart.

My buddy uses only reflectix for his sleeping pad, but I need more padding that that, so I use a BA inflatable. Your idea is a light, smart way to make a summer bag into a shoulder-season rig --or to help a kid upgrade a bag that his folks aren't going to replace right away. Z-lite under, Reflectix inside... could be the ticket.

I use the reflective bubble insulation inside the bag. I'm using InfraStop foil insulation, looks like another brand. The material is precut in 24" widths. I use one on top and one on bottom.

You want this stuff as close to the source heat is escaping to work best. The heat source is you. It's the same principle as the survival blankets but this stuff can be reused and keeping the large air gap between top and bottom doesn't cause any clamminess like a vapor barrier. Don't get me wrong if I needed the vapor barrier I would use it but I like to be perfectly comfortable if possible. This gives me more options. I also like the way it rolls up and packs. The survival blankets seem to be more of a one-time use for just that, survival.

I spoke with the place I got it from and there is a flexible sheet like material they offer that can be stitched together to make a bag w/ ventilation. I got a sample. Looks promising but there are no small sizes available for it. I think it’s the same stuff used in some of the clothing.

Edited by HighPeaks on 05/17/2013 19:29:08 MDT.