Most cattleyas and all encyclias that I know of can take that kind of heat. I don't grow cymbidiums so I really don't know about them. Both catts and encyclias like to dry out between waterings but don't let them stay dry too long in this heat. Mine are in very fast drying medium and I water three times a week during the summer. But slower drying mediums would require watering less. If any of them have a lot of aerial roots, you can mist the aerial roots occasionally to provide extra moisture. You don't need to mist the leaves, it doesn't help the plant much and it can encourage fungus.