From the beginning, it was first attached to THE FLAT SCREEN TV across the top edge of the TV.
Heat rises. There was no problem
When I moved, I had to detach that double adhesive strip, so since then it sits on the pedestal of the TV.
Same TV all this time. It is powered by the TV, I wondered about getting a USB phone block to see if that would power it more securely, but I will see about cleaning it
Addendum. I just went and unplugged the device and looked. There are no vents, no openings other than the USB and HDMI ports on the device. What is there to clean?