I have a 25F sleeping bag can I use it...
I have a 25F sleeping bag can I use it with this and go camping in the snow and be fine on a cold night or this bivy only works to protect from rain but not from cold?
I personally have a 15F and I do just fine. It isn't designed to keep out the cold but the properties of the fabric do help in heat retention. The key to sleeping warm in the snow is a quality sleeping pad.