Since The North Face Women's Aleutian 20 Degree Synthetic Sleeping Bag has a roomy mummy cut and a zipper that lets you turn it into a blanket you can keep it zipped to stay warm on late fall camping trips and you can unzip it for a bit of warmth on summer nights under the stars. The quick drying synthetic insulation contains 30% post consumer recycled material so you don't have to choose between staying warm and being green. Comfort rated to 20F, with a lower limit of 8F, the Aleutian lets you sleep shiver free from mid spring to late fall. While a night spent outdoors in single digit temps might sound possible, you'll want to have a thermal bag liner with you to pair with the Aleutian. Heatseeker Eco synthetic insulation minimizes heat loss, and the draft collar reduces the heat escaping from around your shoulders. The mummy cut is generous so have ample room to flip and flop throughout the night. You can enter this bag from either the left or the right side, and the long side zipper that goes all the way around the wraparound toe box turns it into a blanket if you want to share warmth with another in your tent.