My Hades Canyon with Intel Core i7-8809G will hit 90C almost instantly when I open an app (e.g. Chrome), and then drop back to its normal temperature about 13C. But the fan will start immediately (because it hits 90C), and will remain running for a while, although the temperature drops after 1-2 secs.
I have all the updated drivers including the BIOS from Intel. Running a fresh copy of Windows 10 Pro updated.