In my opinion, there really isn't much to be done for a horse to help it stay cool, other than providing shade, ventilation and plenty of water. As long as the basics are provided, a horse will go where it is most comfortable. (I don't think there's anything more peaceful-looking than a pair of horses standing together under a shade tree, side by side with one facing this way and the other facing that way, so that there is a tail to swish flies off the other one's head and neck. I wish I had a photo of that to show you, but I don't. It defines "cooperation".)
Our horses have access to a large pasture as well as the barn and a run-in shed, and the pasture is ringed by woods and has a small grove of trees in the middle, so "shade" and "ventilation" are taken care of.
The pond has shrunk to the point that the horses no longer have access to the water. They have a total of four water troughs that we check and fill in the morning and evening.
Ella plays in the water troughs, swishing her head back and forth to splash the water on her chest and generally have a cool fun party. She can almost empty a trough doing this, which is why we refill them twice a day.
With a name like Splash, you know he likes to play in the water too. He enjoyed pawing the water in the pond, back when there was water.
When hubby fills the trough, Ella and Splash often come over so he can squirt them with the hose.
I put fly masks on two of the horses. Dakota in particular has his on every day, because the pink skin around his eyes tends to sunburn very easily. Preventing sunburn isn't usually the function of a fly mask, but it works. His nose still sunburns though. He won't allow me to put sunscreen on his nose.
They all spend the afternoon in the barn, which has the deepest shade they can find. The spot way in the back of the barn is the most prized, and whichever horse gets there first doesn't want to give it up for anything.
The sustained heat is making them grumpy and cranky though. Usually they get along well, but there have been more spats lately. (I have to admit that the people are getting grumpy and cranky too.)
If you have any other suggestions of how to keep animals cool in this hot hot weather, please leave a comment below.