Re: To all rack setup users . . .
If you can, space them out from eachother. Make use all tube devices have pleanty of room to breathe. Second, get a nice quite but high powered electric fan. With the volume you're playing at, it shouldnt be noticable at all.
Edit: It should be noted that I never had a rack or used one, Im just giving blind tips. If there's a widow there, move it by the window and set a fan up to blow at it so the heat escapes out the window. If you cant do that or any of it for that matter, take everything out of the rack and space it all out so that they're at least a foot away from eachother and make sure they can still vent well where you put them. That will at least give you an indication of how everything is heating up and what the main factor could be,