to answer the original question...

in the long run, your plants will be fine; just give them a week or so, and they'll be back into full swing.

also, if your lights are at 2 feet, there's almost no way your getting radiant burns... i'm using one in the basement, 8 inches from small plants radiant temp of 90 degrees, with almost no ventilation. i have no burns...

so, i'd say your problem is ambient heat; a solution would be to make a cool tube for you mh, to suck out the hot air from the bulb, or, get a bigger exhaust fan, cut a hole to create a passive intake. this will lower your temps to whatever your intake temp is, depending on the size of your fan...

in my flowerbox, i use a box fan as an exhuast, flowing straight into my room. i cut holes in the bottom of the box to allow a return... sooo... now that it is cold out side, and we have a buck stove for heat, the house is usually 55-60 degrees. in my room, the cool air is replaced by the hot air of the box. the result is a nice and even 72 degrees, box and room so the light is my heater, which uses 1100w less than a space heater

stoner genious

love, kp