How hot are we talking? If well hydrated, plants will continue to respire efficiently up to about 35 C. It's true that after that many enzymes stop working, but if it's only for a short period they can cope. The measures already mentioned will all help, especially shade from outside, and increased ventilation.
Posts
The measures already mentioned will all help, especially shade from outside, and increased ventilation.
"Have nothing in your garden that you don't know to be useful, or believe to be beautiful."