Add a dedicated cooling fan. A 80mm or 120mm 12V computer fan works perfectly. Wire it to the output terminals of the HYS3C210CS (it will run when the PSU is on). Mount the fan blowing onto the vented side of the power supply. This alone can drop temperatures by 20°C.
: If the device connected to the PSU requires more wattage than the hys3c210cs power supply hot