Do all bears hibernate, even the ones that live in a climate that is warm all year?

The polar bear does not hibernate!

Are you sure ? I just saw something on polar bears, and I'm fairly certain that they do.

Not many bears live in warm climates, but for those who do, they may take some long naps from time to time, but don't actually hibernate. Catty

Pregnant polar bear females are the
only polar bears who will enter a
winter den and hibernate for any
length of time.

Good way to get through pregnancy!!!!!

I just thought I'd finally supply a reference for this.

Ursus maritimus
The boars do not generally hibernate, but remain active for most of the year. The pregnant females are the exception to this, however. They go through a denning and hibernation period, just like that of the black, brown, and other bears.