My Dell XPS 13 (Model 9360) has an i7-7560U Kaby Lake CPU and Windows 10 x64. Soon after receipt I noticed that the fan would often run for extended periods, even with the machine supposedly idling. Also, the chassis was quite warm on top and very hot on the bottom. On installing HWInfo I found that during these times the CPU cores were around 90 degrees C !! After useless go-rounds with support I finally discovered what I think is the problem and its solution.
The apparent culprit is the Intel "Local Management Service", launched via LMS.EXE. This has a decade-long history of spurious high-CPU usage and other problems. It is evidently of use only in corporate environments, so a home user can safely disable it. Get to Windows services management (eg. by running services.msc). Locate the service "Intel Management and Security Application - Local Management Service". Open its properties, stop the service, and set its startup type to "Disabled".
It's probably also a good idea to delete "C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\lms.exe".
This appears to have solved the problem on my machine, though some folks have reported that it recurs.
Rant: How could LMS hogging the CPU still be an issue after more than a decade? Even if Intel doesn't care, how could Dell not know about it? How could they send out new high-end laptops with such a killer problem? And why are there so very few reports on it? My XPS 13 is completely stock. As so often with these things I am baffled and amazed, and certainly angry over the time it has cost me. I spent top dollar to have *no* such problems (on a gift, no less).