You could use two layers. It will make your quilt heavier. I live in Wisconsin and it gets cold here. One layer on warm and natural isn't enough for me. Everyone else in the house is ok with it, but I'm always cold. The next quilt I make for myself is going to be two layers of batting(I'm thinking warm and natural and a poly). They do make a warm and bright that is poly so it will hold the heat in more but is close to the same thickness as warm and natural.