You need to slow down, most problems can be worked out if you slow down ant think. If you got the 400 watt dimmable that I suggested then just turn it down to 50% an the heat should be more than manageable until you improve your design. If you have a winged reflector a great way to keep them cool is get yourself a small pc fan like grow demon suggested but what I did was mount it at the end of the fixture with paper clips blowing directly back at the bulb, direct your oscilating fan on the ground blowing the same direction and up, it makes a little vortex of air movement going up and away an helps greatly. I ran a 600 watt in a 30x30 closet with a winged reflector this way with a passive intake and a 6" inline fan for exhaust. Get your airflow corrected and you will be fine