I agree with the third answer with one exception. If you have a horse that's breed is use to warm weather then you probably need a blanket in the winter.
There are other uses to blankets as well. I use a fly sheet for when the flies are really bad and I use the same fly sheet when it is icy because we get a lot of ice in the winter and instead of using a thick heavy blanket to keep him warm I use a fly sheet just to keep him dry he can stay warm on his own.
Maybe if you have a field with no trees or no shelter at all, get a lean-to. An open type of building with 2 sides and a roof where 2 sides are open. This can be used as a wind break or to get in out of a really bad storm. But don't be surprised if its 130 degrees and the horse is in the sun (flies), or if its -10 degrees and the wind is blowing and your horse has his but to the wide and is just standing there. All these are what a horse does. The purpose to a lean-to is to give your horse an escape just in case he wants to use it!!! Options are always good and happy horse loving
There are other uses to blankets as well. I use a fly sheet for when the flies are really bad and I use the same fly sheet when it is icy because we get a lot of ice in the winter and instead of using a thick heavy blanket to keep him warm I use a fly sheet just to keep him dry he can stay warm on his own.
Maybe if you have a field with no trees or no shelter at all, get a lean-to. An open type of building with 2 sides and a roof where 2 sides are open. This can be used as a wind break or to get in out of a really bad storm. But don't be surprised if its 130 degrees and the horse is in the sun (flies), or if its -10 degrees and the wind is blowing and your horse has his but to the wide and is just standing there. All these are what a horse does. The purpose to a lean-to is to give your horse an escape just in case he wants to use it!!! Options are always good and happy horse loving