VOA慢速英语20060711b

SCIENCE IN THE NEWS - While Other Threats Make the News, Heat May Be Nature's Deadliest KillerBy Oliver Chanler and Nancy Steinbach

Broadcast: Mon, 10 Jul 2006 16:00:00 UTC

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty².

VOICE TWO:

And I'm Faith Lapidus. This week, we tell about some health problems linked to extreme heat. We also tell about what to do to prevent and treat these problems.

(MUSIC)

VOICE ONE:

Extremely hot weather is common in many parts of the world. Although hot weather just makes most people hot, it can cause medical problems -- and death.

Floods, storms and other natural events kill thousands of people every year. And, as expected, we hear much about them in news reports. We generally hear little, however, about what experts say may be nature's deadliest killer¹ -- heat.


A student athlete is treated for heat exhaustion³

Health experts say that between nineteen seventy-nine and nineteen ninety-nine, extremely hot weather killed more than eight thousand people in the United States. In that period, more Americans died from extreme heat than from severe storms, lightning, floods and earthquakes together. And in nineteen ninety-five, more than six hundred people died in a period of extremely hot weather in one city -- Chicago, Illinois.

VOICE TWO:

To measure extreme heat, weather experts have developed the Mean Heat Index⁴. It measures the average of how it felt all day on an extremely hot day.

Experts say it is the total heat of a hot day or several hot days that can affect health. Several hot days are considered a heat wave. Experts say heat waves often become deadly when the nighttime temperature does not drop much from the highest daytime temperature. This causes intense⁵ stress on the human body.

Doctors say people can do many things to protect themselves from the dangers of extreme heat. Stay out of the sun, if possible. Drink lots of cool water. Wear light-colored clothing made of natural materials. Make sure the clothing is loose, permitting freedom of movement. And learn the danger signs of the medical problems that are linked to heat.

VOICE ONE:

The most common medical problem caused by hot weather is heat stress. Usually, it also is the least severe. The causes of heat stress include physical work or exercise, heavy clothes, hot weather or high humidity⁶. Humidity is the amount of water in the air.

Several of these conditions together can raise a person's body temperature above safe limits. The person perspires⁷ heavily, losing large amounts of body water and salt.

For most people, the only result of heat stress is muscle pain. The pain is a warning that the body is becoming too hot. Doctors say drinking water will help the pain disappear after the body again has the right amounts of water and salt. For some people, however, the result is more serious. For people who are not in good health, heat can make an existing medical problem worse.

VOICE TWO:

For example, doctors say some people face a greatly increased danger from heat stress. These people have a weak or damaged heart, high blood pressure, or other problems of the blood system. Severe heat can help cause a heart attack or stroke⁸. Health experts say this is the most common cause of death linked to hot weather.

Doctors also say severe heat increases problems for small children, older people and people suffering from the disease⁹ diabetes¹⁰. It also is bad for people who weigh too much and have too much body fat, and for people who drink alcohol¹¹. Hot weather also increases dangers for people who must take medicine for high blood pressure, poor blood flow, nervousness or depression.

(MUSIC)

VOICE ONE:

If heat stress is not treated, it can lead to a more serious problem called heat exhaustion. Perspiration¹² is one of the body's defenses against heat. That is how the body releases¹³ water to cool the skin. However, a person suffering from heat exhaustion loses too much water through perspiration. The person becomes dehydrated.

Dehydration¹⁴ limits a person's ability to work and think. Experts say a reduction¹⁵ of only four or five percent in body water leads to a drop of twenty to thirty percent in work ability. The loss of salt through perspiration also reduces the amount of work that muscles can do.

VOICE TWO:

A person suffering from heat exhaustion feels weak and extremely tired. He or she may have trouble walking normally¹⁶. Heat exhaustion also may produce a general feeling of sickness, a fast heartbeat, breathing problems, and pain in the head, chest or stomach. Doctors say people suffering from these problems should move to a cool place and drink water.

Heat exhaustion can develop quickly. But it also can develop slowly, over several days. Doctors call this disorder¹⁷ dehydration exhaustion. Each day, a person's body loses only a little more water than is taken in. The person may not even know the problem is developing. But if the problem continues for several days, the effects will be the same as the usual kind of heat exhaustion. The treatment for dehydration exhaustion is the same as for heat exhaustion. Drink large amounts of water, and rest in a cool place.

(MUSIC)

VOICE ONE:

Heat exhaustion can lead to heat stroke if it is not treated. With heat stroke, the body temperature rises to more than forty degrees Celsius¹⁸.

The body stops perspiring¹⁹. And the skin becomes dry and very hot. A person may even become unconscious, not knowing what is happening.

Doctors say the body's tissues²⁰ and organs begin to cook when body temperature is higher than forty-two degrees Celsius. Permanent brain damage and death may result. Immediate²¹ medical help is necessary for someone with heat stroke. Doctors say immediate treatment is necessary or the person could die before help arrives.

VOICE TWO:

Immediate treatment should begin by moving the victim out of the sun. Raise the person's feet up about thirty centimeters. Then, take off the person's clothing. Put water on the body. And place pieces of ice in areas where blood passageways are close to the skin. These areas include the back of the neck and under the arms. The purpose is to cool the victim as quickly as possible to stop the body's temperature from increasing.

Experts say it is important to know the danger signs of each of the medical disorders²² linked to hot weather. And they say you should know what to do if the signs appear.

(MUSIC)

VOICE ONE:

Experts say water is important for many health reasons. The body itself is mostly water -- more than sixty-five percent water. Water in blood carries hormones²³ and antibodies through the body. Water in urine carries away waste materials. Water is also needed for cooling the body on hot days, and when we are working or exercising. Water carries body heat to the surface of the skin. There, the heat is lost through perspiration.

Health experts say adults should drink about two liters²⁴ of water each day to replace all the body water lost in liquid wastes and perspiration. They say people should drink more than that in hot weather.

Experts say it is especially important to drink before, during and after exercise. They say we should drink water even before we start to feel like we need something to drink. This is because we sometimes do not feel thirsty until we already have lost a lot of body liquid.

VOICE TWO:

In hot weather, drinking cold liquids is best. They do more than just replace lost body water. Cold liquids also help cool us faster than warm liquids. This is because they take up more heat inside the body and carry it away faster.

Yet experts say that sweet drinks are not good to drink in hot weather. The sugar slows the liquid from getting into the blood system. Tea and coffee also are not effective. Doctors also warn against alcoholic²⁵ drinks. Alcohol speeds the loss of body water through liquid wastes.

VOICE ONE:

In addition to drinking cool water, doctors say there are other things that can protect against the health dangers of heat. Stay out of the sun, if possible. Wear loose, lightweight and light-colored clothes. Wear a hat or other head cover while in the sun. Eat fewer hot and heavy foods. If possible, cook foods during cooler times of the day. Also, rest more often. Physical activity produces body heat.

Experts say these simple steps can prevent the dangerous health problems linked to heat. They will prevent sickness, help you feel better and may even save your life.

(MUSIC)

VOICE TWO:

This SCIENCE IN THE NEWS program was written by Oliver Chanler and Nancy Steinbach. It was produced by Brianna Blake. I'm Faith Lapidus.

VOICE ONE:

And I'm Bob Doughty. Join us again next week for more news about science, in Special English, on the Voice of America.

1 killer   

n.杀人者，杀人犯，杀手，屠杀者

参考例句：

• Heart attacks have become Britain's No.1 killer disease.心脏病已成为英国的头号致命疾病。
• The bulk of the evidence points to him as her killer.大量证据证明是他杀死她的。

2 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

3 exhaustion   

n.耗尽枯竭，疲惫，筋疲力尽，竭尽，详尽无遗的论述

参考例句：

• She slept the sleep of exhaustion.她因疲劳而酣睡。
• His exhaustion was obvious when he fell asleep standing.他站着睡着了，显然是太累了。

4 index   

n.食指；索引；标志；指数；v.把...编索引

参考例句：

• Performonce is an index of ability.成绩是能力的标志。
• Manner of walking gives an index to one's charactor.走路的姿态可反应出人的性格。

5 intense   

adj.认真的，专注的；强烈的；紧张的；热情的

参考例句：

• Susan was an intense young lady.苏珊是一个热情的年轻姑娘。
• The quarrel caused her intense unhappiness.争吵令她极其不快。

6 humidity   

n.湿度，潮湿，湿气

参考例句：

• The house is not comfortable tonight ,because of the high humidity.由于湿度高，今晚屋子里不舒服。
• It's difficult to work because of the humidity.由于空气潮湿，工作很困难。

7 perspires   

v.出汗，流汗( perspire的第三人称单数 )

参考例句：

• The latter has neither hens nor chicks, and only thinks of himself and perspires verdigris. 那风信公鸡既没有母鸡，也没有小鸡。他只想着自己，满身铜绿！ 来自互联网
• On an average day you take 15,000 steps and foot perspires 200 ml of sweat. 平均每一天你的脚要迈15,000步，同时分泌出200毫升的汗液。 来自互联网

8 stroke   

n.笔画，击打，连续的动作，中风，心跳；vt.奉承，轻抚； vi.击打，心跳...

参考例句：

• He drove in a nail with one stroke of the hammer.他一锤就把钉子敲进去了。
• He broke the lock with one stroke of the hammer.他一锤就把锁砸坏了。

9 disease   

n.疾病，弊端

参考例句：

• The doctors are trying to stamp out the disease.医生正在尽力消灭这种疾病。
• He fought against the disease for a long time.他同疾病做了长时间的斗争。

10 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。

11 alcohol   

n.酒精，乙醇；含酒精的饮料

参考例句：

• The law forbids shops to sell alcohol to minors.法律禁止商店向未成年者出售含酒精的饮料。
• The alcohol is industrial.这些酒精是供工业用的。

12 perspiration   

n.汗水；出汗

参考例句：

• It is so hot that my clothes are wet with perspiration.天太热了，我的衣服被汗水湿透了。
• The perspiration was running down my back.汗从我背上淌下来。

13 releases   

v.释放( release的第三人称单数 )；放开；发布；发行

参考例句：

• Nuclear fission releases tremendous amounts of energy. 核裂变释放出巨大的能量。 来自《现代汉英综合大词典》
• Zemel says that when calcium levels are low, the body releases a hormone that helps squeeze the most out of every available milligram of the mineral. 泽莫尔博士说，当人体中的钙含量偏低时，身体里就会产生一种荷尔蒙，它能帮助肌体最大限度地吸收所摄入的钙。 来自《简明英汉词典》

14 dehydration   

n.脱水，干燥

参考例句：

• He died from severe dehydration.他死于严重脱水。
• The eyes are often retracted from dehydration.眼睛常因脱水而凹陷。

15 reduction   

n.减少，减低，减缩；减少，减低

参考例句：

• Reduction in income tax will be welcomed with open arms.减少所得税将受到热烈欢迎。
• You will have a reduction for cash.付现金可以打折扣。

16 normally   

adv.正常地，通常地

参考例句：

• I normally do all my shopping on Saturdays.我通常在星期六买东西。
• My pulse beats normally.我脉搏正常。

17 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

18 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

19 perspiring   

v.出汗，流汗( perspire的现在分词 )

参考例句：

• He had been working hard and was perspiring profusely. 他一直在努力干活，身上大汗淋漓的。 来自《简明英汉词典》
• So they "went it lively," panting and perspiring with the work. 于是他们就“痛痛快快地比一比”了，结果比得两个人气喘吁吁、汗流浃背。 来自英汉文学 - 汤姆历险

20 tissues   

n.组织( tissue的名词复数 )；薄纸；棉纸；一套

参考例句：

• The teacher showed the students the pictures of brain tissues. 老师给学生们看脑组织的图片。 来自《简明英汉词典》
• Give some face tissues to me. 给我些面巾纸。 来自《简明英汉词典》

21 immediate   

adj.立即的；直接的，最接近的；紧靠的

参考例句：

• His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
• We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。

22 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》

23 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

24 liters   

n.升( liter的名词复数 )

参考例句：

• In the metric system, measurements are made in metres and liters. 在公制中，用米和升作计量单位。 来自《简明英汉词典》
• This can holds five liters of water. 这个容器可装五升水。 来自《简明英汉词典》

25 alcoholic   

adj.（含）酒精的，由酒精引起的；n.酗酒者

参考例句：

• The alcoholic strength of brandy far exceeds that of wine.白兰地的酒精浓度远远超过葡萄酒。
• Alcoholic drinks act as a poison to a child.酒精饮料对小孩犹如毒药。