Hiya…what are the room temps the grow area is in? If the room is warm, can you bring in cooler air thru venting, in line fans?
That is a small space for that light, minimum size for 600 watts is 40" x 40" (1m x1m), up to 48" x 48" (approximately).
is it a vented hood?
Your area is taller, but a good read…
Grow your grow area larger or down size the light.