Mountain Hardwear's UltraLamina +45 Synthetic Sleeping Bag combines durability, light weight and warm-weather performance for canyoneering, water sports, and all other hot day/cold night adventures. The half-length zippers on both sides allow for sitting upright and cooking without leaving the comfort and warmth of your bed.
I used this sleeping bag for the first time this past weekend. I camped on Mt. Haleakala here in Hawaii at about the 7,000 ft. level. The temperature was in the mid 40s. I had layers of clothing on, plus the sleeping bag and I was freezing. Maybe the sleeping bag should be rated +50, also the zipper is made where it goes only half way down. This is very inconvenient when there is very little room to move around, like in a one person tent. I think I'll use this sleeping bag in the summer.