All over the northern hemisphere, millions of animals are tucked up somewhere safe, hibernating through the cold, ready to come up smiling in spring. Bats, marmots, hedgehogs, bears. And not just in the wintry north: animals in the tropics do it too, such as some fruit bats and one primate, the dwarf lemur. It had long been a dream to copy the process in people – and by the 2050s, it had become a reality.
Animals hibernate at different “depths”, with varied reductions in metabolism and body temperature. Arctic squirrels are the champions, dropping their metabolic rate by 98…
