Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,
Speaker 1: I'm Lorn vogel Bomb, and this is a classic episode
Speaker 1: from our archives. We've talked before on the show about
Speaker 1: how various cold blooded animals survive the winter, but in
Speaker 1: this one we shift our focus to birds clearly designed
Speaker 1: to cope with cold weather. Penguins. Their bodies are well insulated,
Speaker 1: but how do their little feet not freeze? Hey brain stuff,
Speaker 1: Lauren vogel Bomb here, how long could you stand on
Speaker 1: Antarctic ice before your bare feet froze solid? A minute?
Speaker 1: Maybe two? If you're an emperor penguin, you can do
Speaker 1: it for two months, and in windchills as low as
Speaker 1: negative seventy five degrees fahrenheit that's about negative sixty degrees celsius.
Speaker 1: Those naked bird feet may look positively frigid, but their
Speaker 1: special circulation acts as a kind of anti freeze to
Speaker 1: keep them just warm enough in environments where we'd get
Speaker 1: frostbite immediately. Penguins are adapt to just for cold temperatures.
Speaker 1: They have specialized super insulating feathers that keep heat in.
Speaker 1: We humans would get frostbite, and penguins place specifically because
Speaker 1: our bodies are adapted to a wider range of temperatures
Speaker 1: to keep our internal body temperature right around ninety eight degrees.
Speaker 1: In the heat and the cold, the blood vessels in
Speaker 1: our skin expand or contract to direct or restrict the
Speaker 1: flow of blood out to our skin. Our organs stop
Speaker 1: working somewhere above one hundred and four degrees fahrenheit that's
Speaker 1: about forty degrees celsius. So when we get warm, our
Speaker 1: blood vessels dilate to circulate more warm blood to the skin,
Speaker 1: where hopefully that heat transfers out into the environment. A
Speaker 1: sweating can help with this, but our organs also stop
Speaker 1: working somewhere below ninety degrees fahrenheit that's about thirty two
Speaker 1: degrees celsius. So when we get cold, most of our
Speaker 1: blood vessels constrict to limit the amount of warm blood
Speaker 1: going to the skin where it would lose more heat,
Speaker 1: and thus keep that warmth circulating in our core areas.
Speaker 1: Our hands, feet, and limbs in particular are full of
Speaker 1: these tiny blood vessels that can either warm up or
Speaker 1: chill off fast. Your hands may even appear paler during
Speaker 1: exposure to freezing weather because there's less blood in them.
Speaker 1: It's been redirected to the core of your body to
Speaker 1: make sure those vital organs stay warm, but penguin legs
Speaker 1: and feet have evolved specifically to lose as little heat
Speaker 1: as possible. Penguin feet hold onto heat by restricting blood
Speaker 1: flow in really cold weather, keeping foot temperature just above freezing.
Speaker 1: Penguin legs work like a heat exchange system. Blood vessels
Speaker 1: to and from the feet are very narrow and woven
Speaker 1: closely together, cooling the blood from the body on the
Speaker 1: way to the feet and heating the blood as it
Speaker 1: returns to the body. Feet get cool blood, so there's
Speaker 1: less heat to lose while the body stays toasty. This
Speaker 1: special ability is part of how penguins keep their eggs
Speaker 1: warm until they hatch. Male emperor penguins incubate a single
Speaker 1: egg on top of their feet for two months in
Speaker 1: the dark of winter while females are out feeding at sea.
Speaker 1: They also cover the egg with a flap of warm
Speaker 1: belly skin called a brood pouch to keep it out
Speaker 1: of the elements, and nurturing doesn't stop there for these
Speaker 1: dedicated dads. If females haven't returned with food by the
Speaker 1: time the chicks hatch, male emperors feed their babies for
Speaker 1: a few days on a kind of milk made from
Speaker 1: special cells inside their throats. Today's episode is based on
Speaker 1: the article why Penguin feet don't freeze on how stuffworks
Speaker 1: dot Com, written by Lorraine fifth Rain. Stuff is production
Speaker 1: of iHeartRadio in partnership with HowStuffWorks dot Com and is
Speaker 1: produced by Tyler Klang. Four more podcasts from my heart Radio,
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Speaker 1: to your favorite shows.