Once again, I need a little advice from some more experienced horse people. We think we need to buy winter blankets for our two horses. We're in Northern Minnesota, so it's gets pretty cold and snowy up here. The horses have run-in shelter only, so (obviously) it's not heated. What type of blankets should we be looking at to keep them warm out in the pasture? Do they rate these things for temperatures, like they do for sleeping bags?

As of now, they almost never go in their run-in, even though it's already been down to 0 degrees here. All advice is greatly appreciated!