As a Florida based instructor, I spend a LOT of time in the heat.  ANY tip that helps me to deal with our toasty temperatures is worth checking out. Here are a few of my favorite tips for keeping cool when it seems like fall will NEVER arrive.

Misty Mate Misters - A great way to beat the heat!
This is by far my favorite tip for keeping cool in the summer months.  In Florida, summer can drag on forever.   To not ride when it is hot outside means that you only ride 3 months out of the year.  At the end of this summer, we followed a suggestion of a FlaHorse.com bulletin board member and purchased a couple of misters.  The poster was using them to cool her barn, but we wanted them to place along a tented area outside of each arena.  The misters point into the arena and give the riders a cool blast every time they pass the fence.   That little cheap hose has made lessons so much more enjoyable for both the riders and the horses. Our school horses love to take breaks under the cooling mist. My only suggestion would be to place them at both ends of the arena if possible. If they wind is blowing the wrong way, you lose the effects.  Check out the website as there are many cool misting toys for sale. I think the fan ring misters would be a great solution for an older horse or a non sweater.
Cost - under $25 for one hose and uses less than 2 gallons per hour. 

Cool Dry shirts - It's about time we treated our sport like a sport!
The clothing industry has made some great improvements in athletic wear in the past few years and the horse industry is slowly catching up with other sports.  If you look at shirts designed for golf or running, you see that they are all advertised as "cool dry" or "dri-fit". Well duh.  Nobody wants to be sweaty!  But, if you walk around horse people, you are bound to see an abundance of t-shirts, regular polos, and sweaty horse people!  Well, the equine clothing collections are now offering shirts made of mesh and dri-fit fabrics, but rarely do you see a shirt for under $30.  Since I'm going to destroy it, I don't like to spend $30 on a barn shirt!  The solution - golf polos and running shirts. You are much more likely to find a golf dri fit shirt for under $20 than a horse polo.  Here are a couple of sites where you can find great bargains on athletic tops.  Look professional at your next clinic without sweating your booty off!

Sierra Trading Post - A fabulous site for all types of athletic clothing. The "running" section is full of great deals on shirts. Under womens polos, check out the Reddington Boca Grande Polo.  Only $9.95!  I love this shirt - very cool and comfortable.  Also, Sierra Trading Post carries some Ariat products at greatly reduced prices.  They have also been known to carry random breeches and boots.  Search for items like "breeches" or "paddock" when visiting the site.

BuyGolfShirts.com - This site sells clima cool shirts at a great prices, and as an added bonus, if you have a large club or barn, you can have them embroidered with your farm logo.