Best answer by Kumar
Yes, but not because they are running hot. While playing they can get quite warm to the touch, even hot; but when silent they should be just a little warm and this is normal as long as they are in a ventilated place. They can be left in this state but they can also be powered down if they will not be used for some days.
In general it is also a good idea to power down most things in the home other than the fridges if travel is for an extended time.