Took everyone's advice, opened it up, found some dust, a bit of cat hair, replaced powdery looking paste with Arctic Silver, reassembled.
Idle temp now 50C. Thanks to all for advice, will try updating bios and using Overdrive to get better fan speed.
Checked specs on A10 mobile, it has TDP of 25 watts vs I3-6100H 35 watts, I5 45 watts, almost double.
Do motherboards designed for Intel cpu's have HSF's greatly superior to those built for AMD's?
They're probably all built in the same Foxconn factory.