Hi Alan, maybe come summer, try to position your Aeonium arboreum in part sun-part shade area. The heat described by Tee is exactly what we get here in our place during summertime. Now that I think about it, my aeoniums survive because they get good shade to dappled light coming from the city trees on the west side when the afternoon heat arrives. And since my garden is on the west side it gets gradual heat build-up. Mostly the ones by the fence gets morning sun then gradually moving towards the other side. I just make it a point to give the succulents a good thorough dousing once or twice a week especially when it just goes beyond 90F and I always do it early in the morning. I know my plants dry up so easily since they are all in containers and most of them in terracotta pots.
I also have an outdoor fountain which I keep running, for some humidity for the plants around it and for the birds & cats that do drop by for a drink.
