1 00:00:01,840 --> 00:00:07,640 Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff, 2 00:00:07,640 --> 00:00:10,600 Speaker 1: I'm Lorn vogel Bomb, and this is a classic episode 3 00:00:10,600 --> 00:00:14,200 Speaker 1: from our archives. We've talked before on the show about 4 00:00:14,200 --> 00:00:17,920 Speaker 1: how various cold blooded animals survive the winter, but in 5 00:00:17,960 --> 00:00:21,600 Speaker 1: this one we shift our focus to birds clearly designed 6 00:00:21,640 --> 00:00:26,040 Speaker 1: to cope with cold weather. Penguins. Their bodies are well insulated, 7 00:00:26,200 --> 00:00:31,640 Speaker 1: but how do their little feet not freeze? Hey brain stuff, 8 00:00:31,680 --> 00:00:34,559 Speaker 1: Lauren vogel Bomb here, how long could you stand on 9 00:00:34,640 --> 00:00:38,519 Speaker 1: Antarctic ice before your bare feet froze solid? A minute? 10 00:00:38,720 --> 00:00:41,640 Speaker 1: Maybe two? If you're an emperor penguin, you can do 11 00:00:41,680 --> 00:00:44,000 Speaker 1: it for two months, and in windchills as low as 12 00:00:44,040 --> 00:00:47,640 Speaker 1: negative seventy five degrees fahrenheit that's about negative sixty degrees celsius. 13 00:00:48,400 --> 00:00:51,400 Speaker 1: Those naked bird feet may look positively frigid, but their 14 00:00:51,479 --> 00:00:54,320 Speaker 1: special circulation acts as a kind of anti freeze to 15 00:00:54,400 --> 00:00:56,720 Speaker 1: keep them just warm enough in environments where we'd get 16 00:00:56,720 --> 00:01:01,560 Speaker 1: frostbite immediately. Penguins are adapt to just for cold temperatures. 17 00:01:01,800 --> 00:01:04,840 Speaker 1: They have specialized super insulating feathers that keep heat in. 18 00:01:05,760 --> 00:01:08,839 Speaker 1: We humans would get frostbite, and penguins place specifically because 19 00:01:08,840 --> 00:01:11,280 Speaker 1: our bodies are adapted to a wider range of temperatures 20 00:01:11,640 --> 00:01:14,679 Speaker 1: to keep our internal body temperature right around ninety eight degrees. 21 00:01:14,760 --> 00:01:17,040 Speaker 1: In the heat and the cold, the blood vessels in 22 00:01:17,080 --> 00:01:20,360 Speaker 1: our skin expand or contract to direct or restrict the 23 00:01:20,360 --> 00:01:23,880 Speaker 1: flow of blood out to our skin. Our organs stop 24 00:01:23,920 --> 00:01:26,679 Speaker 1: working somewhere above one hundred and four degrees fahrenheit that's 25 00:01:26,680 --> 00:01:29,640 Speaker 1: about forty degrees celsius. So when we get warm, our 26 00:01:29,680 --> 00:01:32,880 Speaker 1: blood vessels dilate to circulate more warm blood to the skin, 27 00:01:33,200 --> 00:01:36,399 Speaker 1: where hopefully that heat transfers out into the environment. A 28 00:01:36,440 --> 00:01:39,840 Speaker 1: sweating can help with this, but our organs also stop 29 00:01:39,880 --> 00:01:43,160 Speaker 1: working somewhere below ninety degrees fahrenheit that's about thirty two 30 00:01:43,200 --> 00:01:46,000 Speaker 1: degrees celsius. So when we get cold, most of our 31 00:01:46,000 --> 00:01:48,760 Speaker 1: blood vessels constrict to limit the amount of warm blood 32 00:01:48,800 --> 00:01:50,720 Speaker 1: going to the skin where it would lose more heat, 33 00:01:51,040 --> 00:01:53,960 Speaker 1: and thus keep that warmth circulating in our core areas. 34 00:01:54,680 --> 00:01:57,160 Speaker 1: Our hands, feet, and limbs in particular are full of 35 00:01:57,160 --> 00:01:59,680 Speaker 1: these tiny blood vessels that can either warm up or 36 00:01:59,760 --> 00:02:03,480 Speaker 1: chill off fast. Your hands may even appear paler during 37 00:02:03,520 --> 00:02:06,280 Speaker 1: exposure to freezing weather because there's less blood in them. 38 00:02:06,520 --> 00:02:08,480 Speaker 1: It's been redirected to the core of your body to 39 00:02:08,480 --> 00:02:12,320 Speaker 1: make sure those vital organs stay warm, but penguin legs 40 00:02:12,320 --> 00:02:15,000 Speaker 1: and feet have evolved specifically to lose as little heat 41 00:02:15,000 --> 00:02:18,760 Speaker 1: as possible. Penguin feet hold onto heat by restricting blood 42 00:02:18,760 --> 00:02:22,320 Speaker 1: flow in really cold weather, keeping foot temperature just above freezing. 43 00:02:22,880 --> 00:02:26,280 Speaker 1: Penguin legs work like a heat exchange system. Blood vessels 44 00:02:26,320 --> 00:02:28,440 Speaker 1: to and from the feet are very narrow and woven 45 00:02:28,480 --> 00:02:31,080 Speaker 1: closely together, cooling the blood from the body on the 46 00:02:31,080 --> 00:02:33,080 Speaker 1: way to the feet and heating the blood as it 47 00:02:33,080 --> 00:02:36,120 Speaker 1: returns to the body. Feet get cool blood, so there's 48 00:02:36,200 --> 00:02:40,040 Speaker 1: less heat to lose while the body stays toasty. This 49 00:02:40,120 --> 00:02:42,480 Speaker 1: special ability is part of how penguins keep their eggs 50 00:02:42,560 --> 00:02:46,200 Speaker 1: warm until they hatch. Male emperor penguins incubate a single 51 00:02:46,200 --> 00:02:48,440 Speaker 1: egg on top of their feet for two months in 52 00:02:48,480 --> 00:02:51,160 Speaker 1: the dark of winter while females are out feeding at sea. 53 00:02:51,960 --> 00:02:53,760 Speaker 1: They also cover the egg with a flap of warm 54 00:02:53,840 --> 00:02:56,080 Speaker 1: belly skin called a brood pouch to keep it out 55 00:02:56,120 --> 00:02:59,520 Speaker 1: of the elements, and nurturing doesn't stop there for these 56 00:02:59,520 --> 00:03:02,480 Speaker 1: dedicated dads. If females haven't returned with food by the 57 00:03:02,520 --> 00:03:05,200 Speaker 1: time the chicks hatch, male emperors feed their babies for 58 00:03:05,240 --> 00:03:07,359 Speaker 1: a few days on a kind of milk made from 59 00:03:07,400 --> 00:03:15,240 Speaker 1: special cells inside their throats. Today's episode is based on 60 00:03:15,240 --> 00:03:18,000 Speaker 1: the article why Penguin feet don't freeze on how stuffworks 61 00:03:18,000 --> 00:03:20,919 Speaker 1: dot Com, written by Lorraine fifth Rain. Stuff is production 62 00:03:20,960 --> 00:03:23,519 Speaker 1: of iHeartRadio in partnership with HowStuffWorks dot Com and is 63 00:03:23,560 --> 00:03:26,880 Speaker 1: produced by Tyler Klang. Four more podcasts from my heart Radio, 64 00:03:27,040 --> 00:03:30,000 Speaker 1: visit the iHeartRadio app, Apple Podcasts, or wherever you listen 65 00:03:30,040 --> 00:03:31,000 Speaker 1: to your favorite shows.