I don't know if I would say that Aloe is so much sensitive to heat, I suggest it is more attributed to Yuma's severe arridness. They do pretty well here in Central Florida, surviving 100+ temps, even higher with the heat/humidity index added in. I think the only real difference between West Central Florida and the Sonoran area of Arizona is the humidity, and possibly your high ph and/or salt content of the desert soil. The species growing well here, even in the full sun, are Aloe saponaria, Aloe vera, Aloe veriegata, Aloe ferox, Aloe aristata, and one species I have yet to identify. I have also seen what appears to be Aloe striatula growing wild in spots located near the beach on the East Coast of Central Florida (Cape Canaveral.) Just my two cents worth. If one wants to see photos of them growing and flowering in the full sun here, just email me. We are also having a lot of success with Bulbine. Best to you all, Allen Mr. Allen M. Boatman Instructor of Horticulture Falkenburg Road Jail 520 N. Falkenburg Road Tampa, FL 33619 Office (813) 744-5676 Fax (813) 744-5652