We have a lot of customers in southern Florida, Georgia and Texas who call trying to find the best fly sheet for their hot, humid climates. This is what we hear back from customers who have tried them all.
Tough and Breathable
The WeatherBeeta ComFiTec Ripshield Fly Sheet is a great combination of tough and breathable. The fabric is sheer (you can see through it) but strong. While not being a super stiff fly sheet, it has enough stiffness to the fabric to keep it away from the horse to allow air to flow. We have several customers in southern Florida who swear by this sheet and will use nothing else. The one thing this fly sheet does not do is provide much UV protection.
Soft and Flowy
The fabric is super soft and flowy. It feels like it would be comfortable on a hot day. The fabric reflects the sun and provides good UV protection. It features a detachable neck for full coverage. It stays in place with no leg straps. The only downside to this one is that the fabric isn't quite as tough as some of the others and can snag easily if rubbed up against a fence or tree in pasture.
The Amigo Bug Buster is similar to the Amigo Bug Rug above, but with a few extra features. The Bug Buster's soft flowy fabric is infused with Horseware's No Fly Zone technology so you don't need to spray your horse with fly spray. It also has extra belly coverage to protect your horse's more sensitive areas. The silver color reflects the hot sun away from your horse.
For a more affordable option, try the Mio Combo Fly Sheet by Horseware.