This comment seemed odd so I went looking for the Apple III fan story. Then things got more strange: the Wikipedia article is full of talk about things melting because there's no fan. However, read all the supposed references and nothing appears about overheating or missing fans. Based on the references Apple III initially had reliability issues due to socketed devices (a known bad idea) and use of substandard PCB manufacturing processes.
The fan thing made me scratch my head initially because 8-bit micros pretty much never had fans. Cooling only became an issue generally speaking in the 32-bit generation, some 10 years later.
There are lots of other fanless thin clients already, and they work fine. I have some that work fine as local machines too after I upgraded RAM and storage.