I actually used a large polar fleece blanket before I was given a few coolers from a relative. It served its purpose fine, although it tended to blow around (because it didn't have any straps), which might scare some horses. I now have a Big D double thick polar fleece cooler, and I love it. I have a flannel one as well, but it isn't quite as warm. I'm not sure where you would buy these though, as they were given to me.
| Kubie, Appaloosa (RIP) | Patches, Pinto Arabian Pony | Scotch, Paint Quarterhorse |