Just got back from a 3 day backpack in the Ohlone Wilderness Area near Freemont California. I was using a regular Neoair in an old Walrus Zoid 1 tent with an REI Sub Kilo 20 degree bag. Almost too warm on top, but a little cool underneath. Not enough to keep me awake, but noticeable. My friend had a short Neoair and he experienced the same thing. I was a little disappointed because the low air temp was only about 35 degrees. My theory was that the ground was still cold from a recent cold spell here in Northern California. Doing another backpack at Point Reyes Jan 18th. I'm going to cut up an old yoga mat to put under the torso area and see how that works. Maybe a blue pad would be better, but I don't have one of those. I hate to carry the extra weight, but it's better than being cold.