There are a few comments about combining pads that I find interesting. Here is one:

I'll just add that for whatever reason, placing the foam pad on TOP of your inflatable will be much warmer then placing the same foam pad below

At first I though, how could that be? If the heat loss is to the ground, then what difference does it make which order you put things in. Then again, maybe the first phrase in that sentence is key -- maybe the difference isn't heat loss to the ground, but heat loss to the sides. Is this the case, or am I missing something?

Related to this, is this comment (on a different thread):

On a practical note, I would like to try, "wrapping" the Neoair pad in a thin 1/8" pad, such as the GG Thinlight to cover the sides of the pad all the way around. Without going into the science, I believe this would have a rather noticeable effect on it's ability to be effective against somewhat colder temperatures.

I've thought about such a closed cell/inflatable burrito and I think it would make sense. One advantage to having a thinlight against the ground is that it protects your inflatable. I had pretty much decided to change my sleep system to a Neo-Air combined with a thinlight (which would do double duty as a sit pad) with the thinlight on the bottom. Now I learn that having the thinlight on the bottom may not be as effective as having it on the top (because of heat loss to the side). So I'm considering something similar to what Aaron (the author of the second comment) suggested: a thinlight/neo-air burrito. However, I would prefer simply adding edges to the thinlight (thus making it more of a taco) because I think having both pads is not needed for three season use. I'm adding the thinlight mainly because I want to find a new use for my sit pad and protect my neo air; adding a little warmth would be a bonus. What do people think? Is it worth the effort to add the sides, or should I just live with the fact that the pad won't add much warmth (I imagine it will add some, just not as much as if it was flipped upside down).

Edited by rossbleakney on 04/20/2009 12:45:07 MDT.

To answer the question of closed cell on top of inflatable I have found it to be warmer than placing the closed cell on bottom. I believe it is due to the fact that you have to heat the inflatable pad first (with your body heat) and then it seems that the sides are not insulated and you loose some heat due to the extra exposed area. However with the closed cell on top it heats up faster and usually heat can not be lost as easily through it. That has been my experience and understanding.