Question Regarding Heat

I just got a new Kenwood Sovereign 5900. Now the rack I have it in, the only shelf I have left for it to fit on offers almost exactly 2" above. Now on the actual unit there is only 3 small vent areas on the top. While the top of the receiver does get hot, the shelf above it is cool. The receiver has a fan in the back which I guess is taking care of the heat. My question is, is this OK? I know heat is a components worst enemy.

Another quick question. I live right by a major highway and leave my windows open. A lot of dirt/dust gets kicked up and I was told about "breathable" clothes that you can put on the back of the rack to help keep dirt out. This is for a different rack, not the Sovereign. I was wondering if these are safe and worth getting...

Thanks for your help!

James
:confused: