The bag was a Western Mountaineering High Light, rated for 35, but the fabric doesn't claim to be terribly wind resistant. I have slept in it in slightly colder temps, including without any shelter and have had great results. For the weight and cost differential, I'm thinking that any sort of windproof barrier like a lightweight bivy bag or even a trashbag would have made a big difference. It's warmth retention ability has proven itself before, but I learned the hard way that it is just no match for wind.
