SMB has a line called Ventech Elite that are a little cooler. All neoprene boots are going to heat up your horse's legs, though. The only way around it is to leave them off until you're ready to make a run.
Iconoclast. I've been using them on both of my horses this year in 100+ degree temperatures and neither one has started to sweat underneath their boots at all.
I like my RES boots if you are looking for protection. They are a lighter weight neoprene and only during our heaviest workouts is he hot underneath. Plus I've NEVER had dirt in them. I've had all of the different PC SMB's including the VenTech's and I was always finding trapped dirt in them.
If you're looking for protection + great support I believe Iconoclast is the way to go though.
smbs![](<a href="http://s1033.photobucket.com/user/andersmk5/media/horse/20141010_173339-1_zpsv5eadqyj.jpg.html" target="_blank"><img src="http://i1033.photob)
