PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateOKAY ↓ More info and sources below ↓ We’re on PATREON! Join the community ►► https://www.patreon.com/itsokaytobesmart SUBSCRIBE so you don’t miss a video! ►► http://bit.ly/iotbs_sub A human with the metabolism of a hummingbird would need to eat about 80,000 calories a day to survive. That’s because staying warm by making your own heat takes a ton of energy. And that brings up a paradox, because creating your own body heat is incredibly expensive. The largest animals on Earth have to spend most of their day just eating enough to keep their heat engines running. So why aren’t we cold-blooded… like crocodiles? Here’s the science References: https://sites.google.com/view/warm-blooded-references/home ----------- Big Thank you to our Brain Trust Patrons: AlecZero Amy Sowada Andrew Campbell Baerbel Winkler Benjamin Teinby Brian Chang dani bowman David Johnston Dustin Eric Meer Javier Soto Karen Haskell Marcus Tuepker Peter Ehrnstrom Robert Young Roy Lasris Salih Arslan Zenimal Join us on Patreon! https://patreon.com/itsokaytobesmart Twitter http://www.twitter.com/DrJoeHanson http://www.twitter.com/okaytobesmart Instagram http://www.instagram.com/DrJoeHanson http://www.instagram.com/okaytobesmart Merch null Facebook https://www.facebook.com/itsokaytobesmartpbs/