Thank you for reaching out to Alfred!
When a device is running nonstop, it is normal for it to produce some heat. To keep this to a minimum, we suggest you...
1) Use charging accessories from the original manufacturers.
2) Use a charger with timer.
3) Unplug the device for a couple of hours a day if you can.
4) When you don't need Motion Detection, disable the Camera device from your Viewer device with Alfred's Remote Switch:
Hope these help!