I have a few phrags and one of them is pretty sensitive to anything. I dont know much about phrags, but I've been doing some research to figure out what to do with mine. I read that some are very sensitive to the heat. I know I had an ONC that had bud blast from the heat like after 3 days in a west window. If you go to the slipper orchid forums they might have alot more info
Hope this helps!
