Denon 4806 AVR Keep it on all day ?


I just gave my son this Denon 4806 for him to use as 2 Channel TV Audio Only.
It is paired with vintage KLH Model " Baron " 355 Speakers
Will it be a problem if he left it on all day.?
I have heard that these units run hot and would like any opinions about this.
Thank you 
rocky1313