More like a 45 degree bag
The manufacturers' state that the ratings are assuming a person is wearing long underwear, socks and head covering. Now, I don't always sleep that way when hiking but I recently got a chance to test my Hugger#5 bag in the low 40's. I wore exactly what was recommended and I got chilly. The low for the night was 39 degrees. Around that time, I had to put on a light down jacket to stay warm. I just don't think they put enough down in the this bag. I think it should be rated as a 45 degree bag.