Old Gardener, I think if you can put up some screened tarp or even an umbrella or anything that will cover your plants during the hottest part of the day, especially when forecasts go very high, it will help them.
Other than the cacti, most other plants really suffer in our very dry heat. I always try to remember, tropical plants, I do not find them growing naturally in arid desert like conditions which is like our conditions here in super dry Cali especially in summer. Even succulents that hold their own water also suffer with the intense heat.
I got the canopy of city trees that shadows my small garden, so my plants survive the heat onslaught, and I do the watering early in the day, and most of my plants are drought tolerant. But just the same, I do get the badly burnt tips, just too much ambient heat at the height of summer conditions.
In the Philippines where I was from, we got the hot and humid consistent temps year round, but we get on and off rainshowers always, then the thunderstorms and later on typhoons. So the tropical plants survive so well there. Oftentimes you find the smaller plants sheltered by large leaves the size of golf umbrellas. So you can just imagine the protection they get from the heat of the day. And the country is an island archipelago, so we are surrounded by huge bodies of water..similar to Hawaii..thus the effect of humidity there.
So shade and water....tropicals need it.
