How hot is too hot?

Thanks everyone for your replies. When i bought the unit i called Parasound  just to ask if i can leave it on. They said i can leave the amp on 24/7 as it was designed to do that. I didnt ask about heat back then because i didnt notice it at that time.  I sent an email to the Tech dept the other day. Have not heard back yet. 

Some of you say - leave it on, others say turn it off until needed. I can do that - not really a big deal but i still wonder if the amp is faulty somewhere. 

Some of you mentioned an infrared thermometer. Any suggestions for an inexpensive model? I'll probably never use it again for anything else. I should ask my local facebook group to just borrow one.

Your amp is class A/AB: it can getting warm. A Perreaux  gives ( on the display) 65°C and may not be hotter than 90.  After listening switched it in “off”. The warming up will be 30-45 minutes.

I run Class A.  I wouldn't leave it on when not listening.  The heat will shorten the life of components, particularly capacitors that will dry out.
I wouldn't bother with a thermometer, if it's too hot to hold your finger on it, that's too hot.

Once again. I have the Hint 6. It stays on 24/7. It comes nowhere near to being hot even when I'm driving my Dali Opticon 8s at higher spl. I venture you have something wrong.

Heat is normal 6" clearance is very bad should have at least 1foot.Put it on a stand which will be much better for heat dispersion.It should be shut off when not in use 1/2 hour before listing turn it on.Good luck.