Hot Weather Gear

Fans

Home Depot sells a Ryobi battery operated fan that you will see at many dog sport trials. This is the fan I personally use. 

Home Depot also sells the same Ryobi fan with misting capability.

Home Depot sells a Rigid fan that is also popular. 

Shade Cloth

Greenhouse Megastore sells any size you could possibly want at a decent price. I personally use the Aluminet version.

Misc

Clean Run sells a variety of warm weather tools, including car window vents and vent locks for your tailgate.