Help! My Vandas are sunburnt
 

My Vandas were left outside in direct sun for a few hours.m The leaves turned colors...some black. :((. Many are dropping off. However, the roots appear to be fine. Looking for any advice. I am new to Vandas. ***I was not the one to put them outside...someone was trying to be helpfu.

They might survive. Water them normally. Keep them in very bright light, but don't let them burn again.

It was likely the sudden increase in intensity that caused the problem. I transitioned a bunch to full sun here,which is admittedly not as strong as your location, and they've responded wonderfully, growing and spiking like crazy. They did turn that yellow color that's a plant's way of saying "who needs all this chlorophyll here?", but it has been a totally positive change.

A large part of the problem, for high-light-loving plants, is hot leaves, and not light intensity. In still air the sun will heat leaves until they burn. Air moving over the plants carries off the heat and keeps the leaves at the surrounding air temperature. A fan on the plants makes a huge difference in what they can tolerate.