How hot? I turned a Crassula ovata to mush once watering in hot weather. It had been growing here for more than 20 years and was a great speciman. It was clearly stressed and very dry, so I gave in and watered it after the sun was setting and the temperatures were letting up some. By the same time the following day it was soft mush - trunk, branches, leaves - everything. I've done the same thing other times with succulents. They clearly get stressed from lack of water, but they can survive being stressed for a long time. It may not work that way other places, but I've done it too many times. It's really difficult to not give them that water, but I've learned to be really carefully when it gets excessively hot.
