For what it's worth, my Pi's sit inside of Adafruit boxes. Nice clean
design, not a lot of airflow. With JSP Wiki running and doing a few
page hits, temps got to 55-58C on the chip.
I bought these
https://tindie.com/shops/ellisgl/raspberry-pi-copper-heat-sink-kit/
and the temps dropped almost 10 degrees C.
Even without the heat sinks I'm well below chip rating, but the heat
sinks give a little extra. If I was going to run this as a full server,
I would pull the top cover off and clean the cat fur and dust off every
few months.
Plus, they are very pretty, like little smoke stacks on the chips
