If it's too hot, there are a couple of things you can do. Opening the window being one of them... but only if you're sure no light can get in, also that none can get out.

Another is to reposition your exhaust fan, get a tube connecting from it to just next to the light. This way the heat will be better exhausted. If you've already done that, get a bigger exhaust fan.

Another is to use a Co2 set up. this will help your plants thrive better than ever, even in 96f temp's.

Another is to get another fan in there, blowing directly between the bottom of the light and tops of the plants to push the heat away. Although, you should already be doing this.