Let me preface this by saying that the following is completely anecdotal... but:
I have a 3950x CPU and have been monitoring the temperatures (with coretemp) for about one month, a few hours each day, during normal use.
I noticed for the first time, yesterday, that the max temperature hit 105 deg C. Usually, the maximum is around 80 deg C.
I had updated the bios a couple of days prior (0805 to 1002). After noticing the 105 max temp, I went and looked for a bios update on the support page, and noticed that version 1002 had disappeared... Suffice to say, I immediately downgraded back to 0805.
As I said, this could be completely coincidental, or just a freak measurement, bug, whatever; but I'm not taking any chances.