If you look at the bottom of 310.16 you see "correction factors". That is an additional derating you must use if the ambient is above 30c.
As for termination temp, it is usually not really a factor since virtually any breaker above 30a has 75c terminations. 240.4(D) pretty much takes care of those 30a and below. I say "usually" because I am sure you can find cases where this is not true but they are "unusual" ;-)
