Years back, one summer was extremly hot, and tank temps was around 33-34c (90F), fans didnt help at all.... And good month this was temp during day, few degree colder during night.
Is it combination of luck, type of corals, who knows, but nothing dies. Caluastreas, euphilias, cataphilya was stressed and dont look happy at all, anemones too, but all survived, and as soon as temp gets into below 30C range, they start to recovered....
Lost one fish, my chelmon didnt make it, but that can be related to something else, all other fish was ok.
Sadly, chillers are insanely expensive, so i start to worry a bit, summer is comming.....