Air movement is very, very important at all growth stages.

Plant growth stops at 80 degrees ROOT temperature. The plant itself can handle well over 100 if roots are cool.

You do not mention the wattage of the bulbs. At this time it should be the MH bulb. It should be close enough to warm the back of your hand, but not so close as to be uncomfortable at your hand. The leaves reaching for the light is a good sign by the way.