Nineties here in south Louisiana too, and the begonias are loving it. They are mostly in the shade of trees which are cooling by themselves--a few are in more sun away from trees but partially shaded by other plants and a fence. As long as I keep them watered they do fine. Of course I don't grow things that don't like it here like tuberous ones--semi-tuberous do fine--and haven't had any semps for awhile, tho' they would do fine in pots I think. I had them in the ground back in the good old days when it RAINED ONCE IN AWHILE and they tended to rot. Gee, I wish it would rain!