Why Penguin Feet Don't Freeze?
How long could you stand on Antarctic ice before your bare feet froze solid? A minute, maybe two?
在你光着的脚冻僵之前，你能在南极冰面上站多久？一分钟，也许两分钟？
If you're an emperor penguin, you can do it for two months, and in wind chills as low as -75 degrees Fahrenheit (-59.4degrees Celsius).
如果你是帝企鹅，你就可以在零下75华氏度（摄氏59.4度）的风寒中站两个月。
Those naked bird feet may look positively frigid, but their special circulation acts as a kind of antifreeze to keep them just warm enough that they don't freeze.
这些裸露的企鹅脚可能看起来非常寒冷，但它们的特殊循环就像一种防冻剂，使它们保持足够的温度，不会被冻住。
Penguins legs and feet have evolved to lose as little heat as possible.
企鹅的腿和脚已经进化到尽可能少地失去热量。
Penguin feet hold onto heat by restricting blood flow in really cold weather, keeping foot temperature just above freezing.
企鹅的脚在寒冷的天气里通过限制血液流动来保持热量，使脚的温度保持在冰点以上。
Penguin legs work like a heat exchange system; blood vessels to and from the feet are very narrow and woven closely together, cooling the blood from the body on the way to the feet and heating the blood as it returns to the body. Feet get cool blood so there's less heat to lose, while the body stays toasty.
企鹅腿的工作原理就像一个热交换系统；进出脚部的血管非常狭窄，并且紧密地交织在一起，冷却从身体去往脚部的血液，在血液返回身体时加热血液。脚部得到了凉的血液，所以热量流失得少，而身体却能保持温热。
This special ability is part of how penguins keep their eggs warm until they hatch.
这种特殊的能力也是企鹅在孵化前保持蛋得温暖的方法之一。
Humans have the ability to restrict blood flow to their extremities in cold weather too, although not as dramatically as penguins.
人类也有能力在寒冷的天气里限制血液流向四肢，不过没有企鹅那么明显。
Your hands get whiter during freezing weather because there's less blood in them –it's been redirected to the core of your body to make sure vital organs stay warm.
你的手在冰冷的天气里会变得更白，因为手掌中的血液减少了——血液被重新输送到身体的核心部位，以确保重要器官保持温暖。
2025年12月30日于经典龙苑
