Review on Versatile 7-in-1 USB C Hub Adapter: Compatible with MacBook Pro, Windows, Chromebook, Dell XPS, Thunderbolt 3 and More - Includes 4K HDMI, 3 USB 3.0, SD & microSD Card Reader, and 87W Charging by Chad Myers

I use a Transcend 64GB SD card as convenient external storage for my MacBook Pro 15" 2016. I keep the SD card constantly connected to the hub because I only write to and read from the SD card about once a month.I keep the hub plugged into one of the USB-C ports all the time, but I don't use the hub to powering my macbook very hot to the touch and wasn't sure what was causing the problem as nothing other than the inserted sd card was plugged into the hub, I removed the sd card and the hub cooled down after about 10 minutes I then used a standard USB reader to mount the SD cards into a MacBook and the SD card stayed cool after a few hours.Update: Testing the same SD card with Anker 2 in 1 Small Reader and OWC Travel Dock. No heat from either Devices.