Thanks Elaine. I'm used to dealing with the sun at this time of year with shade cloth canopies and relocation of the potted tomatoes into shade. But this single plant, the Cherokee Purple, is especially needy. It's in-ground and heavily mulched. Won't be planting it again; water is way too scarce here for divas.
Different varieties respond differently to heat, aridity and altitude. One variety's fruit literally cooked on the vine. Others simply stop growing until August. Smaller fruits do best. Always experimenting!