I bought one of the early all in one Mactintosh computers and used it relentlessly for many years, it never got hot at all... finally put it to work in a very high load application for another eleven years where it performed twenty four hours a day every single day of those eleven years at full load and never ever got above room temperature. Not once.
I was so impressed with the whole Apple experience that I have owned many more since.
That little Mac spent those eleven years propping up one end of a heavily laden bookshelf in the office.
The first CASA... Computer Aided Shelving Application
Kind regards to all who did real things with their computers.
Russell1