door of the van left open, upper part of thing still not sealed up, and the only additional gear needed was a hoodie, cheapo sweat pants and wearing my tennis shoes. I'm certain I can get this shelter/sleep-gear system down to 0F, 8 lbs max up in a hammock, and 10F down on the frozen ground. If I can find debris that's not soaking wet, I can handle 0F on the ground, too. Not sure, the total may be only 7 lbs. . Even in summer you have to take a pad, tarp, jacket, at least 2 lbs and you'll be down there with the bugs, heat, sticks, stones, and snakes, mud. A hammock is going to be another lb. so for 5 more lbs, you get another 50F degrees of protection from cold, wind, rain.