Question USB 3.x flash drive is hot when connected ?

My USB 3.x flash drive feels hot when inserted, even when I don't do any transfer.

I usully use drives with plastic cases so I didn't think about it, but when I bought a SanDisk 64G drive with full metal case it feels really hot.

An old USB 2.0 drive is inserted into the same USB port, but its temp remains normal even after a movie file transfer.

Do your USB 3.x flash drive become hot while you are using it?
 
The USB drive in question

i-sandisk-ultra-luxe-64gb-usb-3-1-srebrny-sdcz74064gg46-1.jpg
 
I have a USB 3.0x drive that gets fairly hot, but I not enough to be painful. I just chalk it up to the thing being small and consuming pretty much as much power as USB 3.x will provide.
What makes me perplexed is that I'm currently using a USB 2.0 port (5V, 500mA), not the USB 3.x with higher power output. Not sure why the drive is hot though.