I guessing they're falling off because of heat, lower 90's expected for the next couple of days....and thats in the shade. I'm sure the heat index will be in the upper 90's.
Any tips on how to keep these plants "cool"?
Are you growing varieties developed for warmer climates?
I wouldn't be worried if only a few blossoms are dropping. Low 90s shouldn't cause all or even most of the blossoms to drop. I don't start having problems until the temperatures are above 95 for a few days and even then I still get some flowers to set fruit.