Mykel said something that made me think. I can’t quote exactly how she phrased it, but Mykel said that a question she often asks her students is, “What do you want to achieve in your time with your horse.”
Coat Shedding
It evolved that horses are more comfortable at colder temperatures than warmer ones. Their thermal neutral temperature range varies between 5 and 12 deg C. Whereas humans have a comfortable temperature around 20-22 deg C. I won’t go into how this works, but the way a horse’s coat grows is part of the mechanism. It also helps that horses primarily breathe through their nose and not their mouth when it comes to reducing heat loss.