S/H culture and the Sun/heat

[Pilot]

I grow all of my orchids (mostly phals) in s/h and they have been doing extremely well-- every single one of them has bloomed for me and are growing strong and healthy.

However, i recently moved to a new home and though I'm appreciative of the sun room, I'm finding it difficult to regulate and control the temp. In Colorado, our sun is awfully intense and can heat up a glass room, even with very cold temps outside, very easily.

I have my plants on a tall wire rack, like those you find in the restaurant industry. And late in the day, near sunset, the pots get direct sun. I noticed that the pots can get pretty warm.

What can do I to protect my plants and ward off the excess heat to the clear plastic pots?

Also, how warm is too warm for these plants (again, mostly phals)? So far, I see no negative effects but I really don't want to kill off roots because of excessive heat.

Thank you.