A question from a fellow grower:
how far away does a 60 watt lightbulb have to be from the plants?
Place your hand, palm down under the light. Whatever distance you can hold you hand there, comfortably; Is as close as you can place the lamp above your plants.
If it is too hot for the back of your hand; It is too hot for your marijuana plants. Raise it an inch! 
Try again.
What kind of 60 watt light bulb? Incandescent, fluorescent, led, or other?