The lifetime is specified at the upper limit temp. That is, an 85C
rated electrolytic is gauranteed to live for its rated lifetime when
run under bias at 85C. It may live longer ...
The lifetime follows an Arrhenius activation law, so running the caps
at lower temps dramatically increases the lifetime. That is, the
lifetime increases by orders of magnitude as the operating temperature
decreases.
You can get different temp ratings for the caps. For cheap consumer
junk, 85C is a not uncommon rating. But for industrial equipment,
you're better off getting electrolytics rated 105C or better. Due to
the above activation law, the 105C cap run at room temperature will
have *much* longer lifetime than the 85C cap run at room temperature.