In my experience most receivers don't get hot to the point of needing cooling but if you have it in a very enclosed environment yes cooling might be needed. If you would've listed your receiver model (big fat really doesn't provide much info) and maybe how is it positioned and installed we could provide some more data. Assuming a regular home environment I would say cooling is not needed and the receiver would be best without it.
The only piece of equipment ever I had need to cool is a 6C33C-B amp basically to extend the caps life.
The only piece of equipment ever I had need to cool is a 6C33C-B amp basically to extend the caps life.