Hot sun..that is my enemy here too..but my plants thrive because they get shaded on the hottest part of the day. Even my lantana pouts big time when it gets that 11 am sun..leaves go lanky as it gets so heated, but it recovers once it gets shaded again.
Even with succulents, most can take it but intense sun will kill it. That's why we hardly see any in the desert, only the real tough cacti and extremely drought tolerant ones can survive it. And there are succulents that are dormant too in summer, so no amount of watering or sun can make them thrive at this time of the year.
I have long ago decided to have my plants in containers, so if needed I can move them around. I also water them early in the day, to allow the roots to cool down, before the plant gets toasty warm.
As suggested already, provide shade, mulch, and water early to help the plants.
So far the only plants that I really see enjoying the blazing direct heat of the sun here are my Yuccas, cycads, adeniums, cacti, bougainvillea, plumeria, calamondin tree, sarracenia and tropical milkweed. With Plumeria, have to water it daily, since we get dry heat and hit high 90's to triple digits often. Tropical milkweed does surprisingly okay, as long as I water it everyday. The only caveat, it is such a magnet for aphids. All my other succulents have some shade and gets watered heavily at least twice a week or every other day when it is hitting triple digit here. Consideration has to be made too with younger drought tolerant plants, although drought tolerant and can take the sun, since it is still young, you have to put them in an area where it can get shaded till it gets well acclimated and adjusted to the hot environment. My Sarracenia psittacina survives the heat as long as I have it sitting in distilled water. My other non-succulent plants do okay as well, as long as I water early in the day, at least every other day.
And one other thing I have learned now..not to plant any new ones anymore by June. I only do new plantings in Spring to allow the plant to acclimate in my area. We get little to zero rain here from end of March to November, so it is important to make those new plants acclimate in Spring before the toasty and very dry conditions set in.
