I purchased the thermaquilt to give hammocking a try, as an alternative to using a tent. I didn't want to break the bank and purchase an expensive underquilt, so I purchased this from Grand Trunk. I was a bit concerned being that the rating on this is only 40 and it was going to be in the mid 30's on my trip. To compensate for the difference, I zipped up the thremaquilt so it was two layers hanging below my hammock. I then cinched the drawstrings on the ends and it pulled it up close. I was quite impressed with how well this worked and I never had a cold spot, other than when the thermaquilt moved to the side a little. The fix was easy by just pulling it back under me. Next time I will just attached it with a couple safety pins or velcro to keep it in place. This was such a minor issue and I am not sure that I would even purchase another underquilt other than to cut weight in my pack at some point, or if I was backpacking in super cold temps. I had a great comfortable night in the hammock and I will continue to do so using the thermaquilt.