These are all class D Amps with switching power supplies and although very efficient, the still produce heat. Usually the total combination is about 80% efficient so at 200 watts, total power is 200 X 100/80or 250 watts. So you still have to dissipate 50 watts of heat. If you can touch it but it is very hot it is likely around 60C, at 70C you cannot keep your finger on it. Many Amps have their over temperature settings between 60-70 degrees.
Make sure the space around the amp is clear to aid airflow but in general if the Amp is not cutting out, I would not worry.