How do cold weather creatures (Arctic fish, tundra insects, etc.), keep their metabolism going at the low temperatures they will likely have?
This just occurred to me recently. I have heard about how hypothermia in humans will really slow most body processes down (possibly because of hormones or nerve signals, but still slower.), how chemical reactions, diffusion, etc. sometimes change speeds quite a lot with temperature, and it also seems that smaller creatures in cold water or cold air with no fur and such will pretty easily get cold enough to cause things to slow down.