Complex sentence: Historically there was a question of whether or not bears truly hibernate, since they experience only a modest decline in body temperature (3-5 ° C) compared with what other hibernators undergo (32 ° C +).
Split into simpler sentences: Historically there was a question of whether or not bears truly hibernate. Since they experience only a modest decline in body temperature (3-5 ° C) compared with what other hibernators undergo (32 ° C +).