How hot is hot for a round baler bearing?

I've been shooting my bearings with my $9 laser thermal gun. Very informational. Upper/lower roller bearings are about 110*-120* after making 40-50 bales. Most others were about 110-130*
However, the big chain drive bearing (not sure of the technical name) was 168*.
Is this too hot?

I have also been dumping the PTO button more, even when driving from one windrow to another, thinking it might let them cool off just a few degrees. Advisable? Or am I just wearing out my PTO assemblies faster?

How hot is hot for a round baler bearing?