Looking at your box I see you have some crap sitting on your light, possibly insulating the unit... if you don't want a house fire I may suggest taking all of that stuff off of there and mounting it in a more organized way. As far as heat goes, yeah the mars 300 is pretty warm... it worked well for me being in a closet that was adjacent to the outside in the winter. The cold seeped in and all was well. My autos never came (screw amsterdammarijuanaseeds.com, don't use them!) but ended up doing really well w/ some night nurse. Yes, two of these lights worked fine when I was on a budget, have now done three nice grows with decent yields. No, it isn't magic but good ventilation is key. For me, just keeping the closet door open and the house temp regulated worked fine, even in the summer.
My recommendation: if these are too hot for that little box, just leave the door open or reorganize your life and use a different closet in your place if that is the issue. Maybe look into growing with fluorescent... I have had good luck in tight quarters with those. A couple small tips for the road; your girls may be struggling in those little peat pots because there is no room for roots and they look pretty dry. Try reporting in a bigger pot, it acts as a moisture reservoir. Your light looks pretty far away too. Mine sits about 10" max, but in flower it can be as close as 5" once they are used to that. I see your temp and humidity are within acceptable bounds so I would check into other problems: ph, moisture levels, how much circulation you have. The plants on the left look super dry and possibly experiencing some nute lockout. New sprouts must be kept moist. Also, I am counting 5 fans in that tiny box... you may ne drying out or "wind shearing" your leaves in the wind tunnel friend.
I won't say they are the best lights, but try checking into those things and you can have a successful grow. Don't give up!
Go to a specialty garden shop or research online (plenty of people on this forum have opinions, trust me) if you want a recommendation on a brand of light... I only know mine and that, if you have strong fundamentals, you can grow a ton of bud with em... everything else needs to be strong first though. Peace.