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Why Are We Warm-Blooded?

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; creating your own body heat is incredibly expensive. So, why aren’t cold-blooded… like crocodiles? Here’s the science.

Why Are We Warm-Blooded?

11m 18s

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; creating your own body heat is incredibly expensive. So, why aren’t cold-blooded… like crocodiles? Here’s the science.

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