It would be great to check the heating of the internal components. Since we can stick heat sinks on the chips and rather easily eliminate this overheating problem if it exists. But the device's case is cold so it would be strange if the insides are hot.
1. very modest dimensions of chips and heatsinks,
2. quite small chassis, which is missing ventholes.
Therefore it is simply NOT possible to expel the hot air outside the casing with reasonable speed. You'd better prepare for mounting fans or thermally conductive tapes and drilling holes in the chassis, if you need a working solution against overheating