Sometimes the dust in your USB C port would affect the connection as well. Please try to clean your USB C port with a toothpick.
Unfortunately, converting signals from USB C to different signals would always consume a large amount of computing power heat. We have taken this issue into consideration at the beginning phase of our product design, did our best to reduce the heat on the surface during use.
Safe to touch and safe to use for sure.
If you’re using USB C to HDMI adapter, the HDMI to HDMI cable would also cause the heating problem.
You may try a different HDMI cable, see if you still get the same result.
It's actually a known issue that Mac notebook would be interfered by USB 3 device sometimes. Here is a quote from Apple support article:
"Some USB 3 devices can generate radio frequency interference that can cause Wi-Fi and Bluetooth devices operating in the 2.4GHz band to have issues communicating with your computer. Here are some tips to avoid this issue:
1. If your USB device has a cable long enough that you can move the device, place it away from your Mac—and make sure not to place it behind your Mac, or near the hinge of its display. The antennas for Wi-Fi and Bluetooth are located there, and USB 3 devices placed there might interfere with your wireless connections.
2. If you're using adapters or dongles on a Mac computer with Thunderbolt 3 (USB-C) ports, plug them into the front port on the left side of your Mac, or into the ports on the right side (if your computer has them). These ports are the farthest away from the antennas, making interference less likely.
3. To avoid interference on the 2.4GHz band using Wi-Fi, try using the 5GHz band instead. You can change this on your wireless base station. Bluetooth always uses 2.4GHz, so this alternative isn't available for Bluetooth."