-5 degrees? Not my problem.
I took this bag out on one beast of an inaugural run. I don't really get the name, but I got the fact that it kept me toasty warm with nothing but a waterproof cover and a thin foam pad. Just that to protect me froma thick blanket of snow and the gusty breeze atop a mountain in central Utah near the mouth of Kolob Canyon, in December of 2008. Now I know that Central Utah mountains aren't usually as cold as the Wasatch Range, but this was right after a huge snow storm rolled through and unusually cold weather (dropped to around -5 at one point). I'm not sure what our altitude was, but I think that this trip spoke volumes for the Coulair. I didn't even have a true bivy, just a rain cover to stop any melt from getting in, and I slept pretty much naked in this beast. I actually broke out into a light sweat the first night. So the next night I wore my smart wool thermals and they helped me regulate my temperature a little better and I slept pretty well. I would recommend this bag to my friends. It packed to about the size of an oversized football (cylindrically spoeaking)l, the smallest out of anyone in my group and arguably performed the best. I just hope this bag is as durable as I hope over time. I give it my seal of approval.