Coolers are awesome in the winter! I like to keep my horse fuzzy. Unfortunately that ends up with her being a steamy, sweaty mess after riding her. It took forever to dry her until I discovered the magical powers of coolers, lol. I'm amazed every time I see the condensation on the outside. Looks like morning dew, lol. The dry so quickly.
They also double well as a blanket in the summer to keep them clean the night before the show. It keeps my horse sweat free all night. Although I wouldn't want to try that with a wool cooler. Might be to hot. I believe mine is a fleece/cotton combo.