Temperature sensitivity question

[IowaOrchid]

I need some advice from you as to the sensitivity to temperature when it comes to the cool lovers. I have a Dend. cuthbertsonii and a Dend. jacobsonii. Now it is reccommended that you don't go above 78 but, is this a hard and fast number or if misted a couple of times a day and with a good stiff breeze can they handle up to say 85 if in shade too. I can keep them in my basement which is 74 but I'm sure they would rather be outside in the summer.

Julie