3 A2 How cool is cold

CHAPTER 1 It's Too Cold! TURN ON THE FIRE, PUT ON SOME WARM CLOTHES, AND MAKE YOURSELF A HOT DRINK. THIS BOOK IS GOING TO MAKE YOU FEEL COLD! The weather for the weekend is going to be very cold. We'll see temperatures as low as —15C in some places, and there will be a lot of wind and snow. Driving will be dangerous because of ice on the roads. So wear warm clothes and drive carefully. Weather like this is bad news for many people. Freezing weather makes life difficult. Airports close, trains stop running, and walking on sidewalks becomes difficult because of ice. These problems are bad for everyone living in cold places. But does everyone feel the cold in the same way?

Studies show that cold weather is worse for older people. Older people don't shiver as quickly or as much as younger people. When you shiver, your body makes heat and you get warmer. Thin people feel the cold more than people who are big and heavy. Heavy people have more fat on their bodies. The fat helps their body heat stay inside and keeps them warmer. The cold can be wonderful or terrible. Think about a cold drink full of ice on a hot day, or a cold shower in a freezing bathroom. In this book we're going to look at cold places, how the cold affects our health, people who live in the far north, and animals with "cold blood."

CHAPTER 2 Cold Places WINTER MAY BE COLD WHERE YOU LIVE. BUT IS IT AS COLD AS IN THESE PLACES? International Falls, Minnesota, USA, is known as "The Icebox of the Nation." This town of 7,000 people is the coldest town in the country. In January 2011, the thermometer showed a temperature of —32C! The normal temperature in January is —15C. The city of Yakutsk, in Russia, is the coldest city in the world. The daily high in January is around —50C, but it can get as cold as —64C. And the winters are eight months long. When people get out of their cars here, they do not turn off their engines. They keep the engines going so that they don't freeze. Also, people do not wear metal glasses outside. It is so cold that the metal sticks to their skin, and they cannot take them off.

Antarctica is the driest, windiest, and coldest place on Earth. In July 1983, it was —89.2C. That's the lowest temperature ever recorded on Earth. Very few animals can live in Antarctica, and there are no towns for people, only some science stations. About 20 scientists live at the Vostok Science Station in Antarctica, but they do not live there all year. Antarctica has 90 percent of the world's ice, and in some places the ice goes down more than 4,700 meters! But there is a problem. Warm sea water that gets under the ice is making it melt. If lots of this ice becomes liquid, the seas in the world will get higher. This will mean some towns near the sea will be under the water.

So it can be very cold on Earth. But how cold is it on other planets? It is colder on the planet Mars than it is on Earth. This is because it is usually farther away from the Sun than our world is. The coldest temperature on Mars is —140C. There are eight planets in our solar system. As the planets get farther away from the Sun, they usually get colder. But not always. Neptune is the farthest planet from the Sun, but it is not the coldest. Today, that prize goes to Uranus. The temperature on Uranus is —224C. It is colder than Neptune because the temperature at the center of the planet is colder. Also, it has very strong winds sometimes more than 800 kilometers an hour!

Scientists say that the coldest temperature is —273.15C. This is called 0 Kelvin. Nothing can be colder. The normal temperature in space is about —265C. In 2000, a group of scientists cooled a piece of metal to —273.15C. On that day, that piece of metal was the coldest thing in the universe.