A pure vinyl product, such as that manufactured by WunderGrip, is what you want to use. It looks like the latex and rubber type, but contains no reactive agent that will stain your floors.

My son currently works as a 3rd party engineer for one of the felt rug padding and carpet padding manufacturers Rug Pad USA, Mohawk, Shaw.... and I've actually asked him this same exact issue. I'm a designer down in Savannah GA and our summers are as humid and muggy as they come. I asked him specifically what pads would work to avoid the "Sweating" issue. My clients and I complain about this all the time - the pads get glued to the floor. One of my clients had to replace a portion of their hardwood to fix this issue. He has an engineer background does this for a living, thus most of what he said went over my head....but here's what I gathered... - A 100% felt rug pad is actually recycled polypropylene fibers but it won't ever stain, nor sweat, but the rug has to be large enough not to move. But with smaller rugs, you need to stick with a rubber or latex product to prevent "sweating" and sticking. - Felt and rubber rug pads are made with either synthetic latex (lower cost) or Natural rubber (more expensive), he thought that both should be dry enough that they shouldn't sweat between your floors. So this is what I have been recommending to my clients. I also asked him about the different materials - since I told him one of my clients floors needed to be replaced. Heres what he said "your flooring surface finishes are whats important, not whats underneath them, and to be especially careful with vinyl, acrylic, and laquered finishes. Some PVC padding, not all, can leave an imprint on this type of flooring if they don't get the formula correct, or if they use cheap fillers rather in place of proper materials, or if they haven't been tested on before. Pads that tend stick to floors, melt, sweat, are always made with pvc and essentially all come from low grade suppliers in China." Some food for thought :) - Hope this helps

We bought ours about two years ago at Wal-Mart. I think it was somewhere between $80 and $120 for a queen size. It is a Sunbeam, too. We love the thing. I like a big puffy duvet, but DH can't stand to be so covered up. This works great for us, especially with the separate controls for each side. All we have on the bed in the winter is the heated pad, flannel sheets, an EMPTY duvet cover (for decorative purposes only) and a microfiber blanket. We stay toasty. Also, there is the added benefit of letting the programmable thermostat drop overnight to save money on the heating bill. I thought I might feel the wires, but I don't. Maybe its because we put on the flannel sheets when we put on the heated mattress pad.

nosoccermom, I've had the felt/felt ones before (versus felt/rubber) and unless they are under very large rugs and have heavy furniture on top the rug will move because the felt will slide on tile or hardwood floors. Mtn, I actually ordered the thicker pad for my 10x14 thinner rug and it made a world of difference. It feels thicker and softer, and is not moving or wrinkling, like it used to, at all. Much easier to vaccum too.