A very easy way to fix you problem is by probably getting a more efficient case, doing cable management, and the most important part...
DO NOT PUT YOUR PC ON THE FLOOR NEXT TO YOUR DESK.
Always try to put it on your desk to your right or somewhere, but the worst is the floor, don't even think of putting it on carpet.
I recommend if you get a new case get something NZXT, Corsair, or Coolermaster.