How hot is too hot?

epz, the Hint 6 is an excellent unit. It has a thermal breaker. If it gets too hot it will shut down. If it is not shutting down you are OK.

clearthinker, I think in general you are right. My old Krell KMA 100s were class A and burned out after 20 some odd years. Components are much better now and more heat tolerant. I expect their life span to be longer. 
It seems all the amps I am interested in run hot. In an attempt to improve their life span I use a fan system which you can see on my system page.
My approach to the fan noise was to put the amps in the room under the speakers on a shelf against the ceiling. I did have to put a potentiometer on the fans to slow them down. At full speed I could hear them upstairs.

@epz- As others have mentioned, leave the main power switch on 24/7. That is what Parasound is referring to. Just put it in standby when not in use. That’s pretty standard practice for amps. 

Who was the person that started the story, you should alway leave you audio equipment amp on...Who started this was it Thomas Edison? So he could make more money....or the audio equipment company who says alway leave your audio equipment on....just leave the volume down to zero....WHO....does anybody out there have the person's Name?   The only thing I leave on that's electric in my home is the refrigerator and my electric clock....everything else is shut OFF....yes my microwave to.The clock on my stove is always on....my cable box is off...and I save alot of money on my electric bill.....lol.

Aside from dadork worrying me - because he has the exact same unit and his never gets hot; I am turning off the until from the front "standby" switch every night, and put it on when i use it. I always left the rear panel on/off on. I will try to lower the volume to -0- to see if that helps as was suggested.

Several decades audio repair, and can tell almost instantly whether unit on 24/7 or shut off when not in use.
The heat cooks the components (which are designed for heat to a point) AND the solder, which in units made after 2006 will be Lead-free solder and does poorly in high heat cycle environments.
My experience the solder joints will fail before most components.

Turn it off when not listening, solid state warms up very quickly. I get home and fire up the stereo and it's ready for listening within 15 minutes.
My 3 cents (inflation)