Our 87 year old house get *really* cold. Especially in my sons room. So I set out to find fitted fleece sheets. Not only are the choices limited but the sheets are a little more expensive than I was willing to pay. I purchased 2 yards of camo fabric on clearance from Joanne's and found a helpful tutorial on how to make on myself. The sheet actually came out a little on the big side but it still works great and will help keep my little man warm at night. Here's a link to the tutorial.
Here's a pic of how mine came out: