PaOol,
What is the prognosis on your temps now? You've got a few days to figure out the problem before you need to get your seedlings under serious light. Check out this setup in the photographs. It's clearly a ghetto setup but it fits my closet and my budget. You can see that there is a lot of air flow from a "tornado" type fan at the bottom, set on low. The autoshade has a dual purpose it acts as a wind tunnel and a light tunnel. The air only can escape through the top so the blow-bye cools down the heat that may come from the lighting. The fan at the bottom also blows directly on the pots and sucks some heat away from the roots as the air flow moves up the plant. My ambient room temps are at least 85 and frequently 90 by the end of the day. But with this setup there is very little mixing of the effluent air (at top) and the influent air at bottom.
If your current setup is two rubermaids stacked with CFL ballasts contained inside and 4 little fans pushing recycled warm air at your plants your plants are going to get warm and be slow growers.
Root temp should be your concern. You can heat the green zone up to at least 100 without any problem but the roots should stay cool (80 degrees or less if you can manage).
Here is a suggestion to think about. Your grow case is the inner habitat for your plants. But if you put the grow case in the closet then the closet becomes the habitat for your grow case. If your effluent and influent are mixing in the closet then the Rubbermaids are going to get old warm air inside them. You need to monitor the primary habitat(rubermaids) along with the secondary habitat (closet). Ventilate the closet so that the cool air and warm air don't mix. Use a cardboard crafted ventilation ducts to keep the old and new air from mixing.
I've been using autoflower strains (20/4) so I don't have to worry about absolute darkness and I can let my setup breathe a little more. I also have my plants sleep after sunset so I don't have to worry about daylight fucking up their sleep.