Wiggins61 is right, on all counts. The grease lubed roller or ball bearings can get to about 250 to 300 degrees and still be very happy. The limit, based on the type of grease used, can be a temperature that will blister your finger. That doesn't mean this is normal for your type, so there is nothing wrong with personally discussing your observations with the maintenance chief, and even a wander thru the maintenance manual.