50 C seems like a good ceiling. For extra safety, I use a 2-tiered temperature profile.
My first profile is for > 45 C - it is for 125/500
Then I have a profile with higher priority set for > 50 C at 125/400
I am being really careful since those are battery temps only in 2.2, and the battery is more vulnerable than the CPU, plus takes longer to get that hot. I have had this profile running for over a week, and have never hit it.