XPS 13 overheating when VGA adapter connected to USB-C port

Just bought XPS 13 (9350) updated to latest BIOS 1.3.3.

When I connect USB-C to VGA adapter - in a minute left side of PC starts to overheat, fans starts spinning intensively and battery forecast drops from 13 hours to 1.5h..

I don't even connect a monitor to the adapter, and not connected to OS, as this happens logging into BOIS as well..

If I unplug the adapter - in 30 seconds PC cools down, fans stop.

Is this a normal? It seems I cannot even connect a projector without plugging PC for charging during 1.5h meeting.

I saw some similar issues with XPS 15 here http://en.community.dell.com/support-forums/laptop/f/3518/p/19676323/20899854#20899854 

Anyone faced something similar? Or my device is somehow broken?