Alberto, the Cortese does run relatively cool for class a. Of course there are not that many tubes.
The 10,000 hr life of the F2a tubes also speaks volumes about the conservative design.
While I don't feel a bit of difference in heat with the Shindo playing all day in my room, the ARC 210's with the combined total of 16 6550C's most definitely does warm up the room rather quickly.
Come to think of it, the Lamm M1.2's Class A monoblocks used to idle at 330w and over 700w each when pushing the pedal to the metal. I don't remember having any issues with heat though.
Class A is wonderful but the heat issues with some amps make them a no go in some cases. As much as I wanted to get all Krell amps for my theater, the though of having to sit in there for a few hours at a time with all the krell muscle heating up the room, I had to go with plan B. (Bryston).