There is a three sided shelter. Also it is free choice hay. Not clipped, not blanketed but never outside when colder than freezing during the day. Never lower than 45 inside.
BTW, it's not my horse. She has to rough it outside 24/7 and has lived outside her entire life. It's a friend of mine who is moving her horse outside where it will be in the teens and lower 20s the next two days. Low going down below zero. I was just surprised to hear that a horse could grow that much hair in 24 hours to be warm in those temps.