Linked from
The 13 pages that link to Brown adipose tissue, each with the reason it gives.
HibernationRelated: It helps many mammals rewarm during arousal from hibernation.
EndothermyBroader topic: Its uncoupling protein converts stored fuel into heat rather than ATP.
TorporRelated: Its heat production can help an animal rewarm as torpor ends.
Adipose tissueBroader topic: It contrasts with white fat's primary role in long-term energy storage.
HeterothermyRelated: Its thermogenesis helps animals rewarm after periods of low body temperature.