Skeptical of ratings
I'm always skeptical of bag ratings, but this one is very accurate. My first trip with this bag was a car camping trip when the weather was supposed to be in the 20's, so I took an extra bag just in case. I went to bed wearing my long underwear and knit cap, knowing that I would probably need the other bag before morning. I awoke to a temperature reading of 17 degrees the next morning. I had stayed warm all night! The next couple of nights were in the low 30's and all I needed was dry socks and knit cap. I was also using the BA air core pad and on the coldest night I added a closed cell pad as well. As you can see, I am very pleased with this combination.