Homemade quilt stuffed with wool. All the heat-trapping qualities of a wool blanket, with the comfortable qualities of cotton exterior.
I have several that look exactly like this, made by my great-grandmothers decades ago. They have a few holes in them, but still are the best covers that we have.
That's a cool idea, Spider. We have a quilt (just the woven cloth top part, not the stuffing or bottom layer) that was stitched by my great-great-great-grandmother (don't know how many greats). She made it while walking on the Trail of Tears. It's heir loomed in a box now.