At full Blast, my amps run slightly warm. I attribute it to the huge power supplies that allow the outputs to coast as they alow the electricity through, rather than working hard to extract it from a small power supply. The amps use very little bias, because it is not necessary, and causes heat to be produced. Since the amps a in the next room, I did use a small fan on a Bryston for a while. One interesting design for an amp is the Audire Monarch. It is a tower lined with many output transistors, and has an open bottom to let air rise for cooling out the highly vented top. The design reminds me of the old GE tube amp my family's movie theater used in the 1950's, but could have been even older.. It was 100 watts, about 5 inches thick, at least a foot and a half wide, and about two feet tall. All visible surfaces were totally perforated. Some audiophiles like to open the tops of their amps. This did help my Bryston run cooler.
