Originally Posted by centexwoody
I've used a twin sheet sewn into a folded sleepsack (like they used to require in youth hostels). While not particularly lightweight to carry, it is plenty of cover, especially if the mosquitoes are buzzing & I want something covering most of me. That's midsummer, of course, and I've eyed the Polartec/fleece sleepsacks as a March or September addition.
I use a silk bag liner along with whatever sleeping bag I take. the bag liner is good by itself when it's hot, adds a bit of extra warmth when used with the sleeping bag, and is a lot easier to clean than a sleeping bag.
BTW, a tip for when it's too warm for the bag you have with you is to zip it open completely and spread it out like a quilt over top of you. You can easily adjust the warmth by how far you pull it over yourself.