VOA慢速英语2010年-SCIENCE IN THE NEWS - In Hot Weather,

FAITH LAPIDUS: This is SCIENCE IN THE NEWS, in VOA Special English. I’m Faith Lapidus.

BOB DOUGHTY¹: And I'm Bob Doughty. This week, we tell about health problems linked to extreme heat. We tell what experts suggest to prevent and treat these problems.

(MUSIC)

FAITH LAPIDUS: Extremely hot weather is common in many parts of the world. Although hot weather just makes most people feel hot, it can cause serious medical problems, even death.

Floods, storms and other natural events kill thousands of people every year. So does extreme heat. Experts say heat may be nature’s deadliest killer².

For example, Indian officials blamed extreme heat for killing³ more than two hundred people in late May. Temperatures reached almost fifty degrees Celsius⁴ in several Indian states.

BOB DOUGHTY: Several hot days that follow each other are considered a heat wave. Experts say heat waves often become dangerous when the nighttime temperature does not drop much from the highest daytime temperature. This causes great stress on the human body.

Martha Hartman, age 101, on Saturday during a heat wave in New York. She says she has survived a century without an air conditioner and doesn't see why she needs one now.

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. Also, learn the danger signs of the medical problems linked to heat.

(MUSIC)

FAITH LAPIDUS: The most common health problem linked to hot weather is heat stress. Usually, it is also the least severe. The causes of heat stress include wearing heavy clothing, physical work or exercise, hot weather and high humidity⁵. Humidity is the amount of water in the air.

If several of these conditions are present at the same time, a person’s body temperature may rise above safe levels. The person loses large amounts of body water and salt in perspiration⁶. Perspiration is one of the body’s defenses against heat. It is how the body releases water to cool the skin.

Most people suffer only muscle pain because of heat stress. The pain is a warning that the body is becoming too hot. Doctors say those suffering muscle pain should stop all activity and rest in a cool place. They should also drink cool liquids. Doctors say not to return to physical activity for a few hours because serious conditions could develop.

BOB DOUGHTY: Some people face an increased danger from heat stress. They may have a weak or damaged heart, high blood pressure or other problems of the blood system. Severe heat increases problems for small children, older adults and those who have the disease diabetes⁷.

It is also dangerous for people who weigh too much and have too much body fat, and for people who drink alcohol. Hot weather also increases dangers for people who must take medicine for high blood pressure, poor blood flow, nervousness or depression.

FAITH LAPIDUS: Untreated heat stress can lead to a more serious problem called heat exhaustion⁸. A person suffering from heat exhaustion loses too much water through perspiration. The person becomes dehydrated.

A person suffering heat exhaustion feels weak and extremely tired. He or she may have trouble walking normally. Heat exhaustion may also produce a feeling of sickness, a fast heartbeat, breathing problems and pain in the head, chest or stomach. Doctors say people with such problems should rest quietly in a cool place and drink plenty of water. They also say it may help to wash with cool water.

BOB DOUGHTY: Heat exhaustion can develop quickly. It also can develop slowly, over a period of days. Doctors call this dehydration⁹ exhaustion. Each day, the body loses only a little more water than is taken in. The person may not even know this problem is developing. If the problem continues for several days, the effects will be the same as the usual kind of heat exhaustion.

Experts say even a two percent drop in the body's water supply can cause signs of dehydration. These signs include problems with memory and even simple mathematics.

FAITH LAPIDUS: Dehydration limits a person's ability to work and think. Experts say a reduction 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.

The treatment for dehydration exhaustion is the same as for heat exhaustion. Drink plenty of water and rest in a cool place. Even better, doctors say, drink about two liters of water a day so problems with dehydration will not have a chance to develop.

(MUSIC)

BOB DOUGHTY: Heat exhaustion can lead to heat stroke if it is not treated. Heat stroke is the most serious disorder¹⁰ linked to hot weather. It results when the body is not able to control its temperature. The body’s temperature increases and perspiration fails.

Generally, the body temperature rises to more than forty degrees Celsius. The body stops perspiring¹¹. The skin becomes dry and very hot. A person may become unconscious, not knowing what is happening.

Doctors say tissues and organs begin to cook when the body's temperature is higher than forty-two degrees Celsius. Permanent brain damage and death may result. Someone suffering heat stroke requires immediate¹² medical attention. Doctors say such treatment is necessary or the person could die before help arrives.

FAITH LAPIDUS: The purpose of immediate treatment is to cool the victim as quickly as possible to stop the body temperature from increasing. Begin by moving the victim out of the sun. Raise the person’s feet up about thirty centimeters. Take off the victim’s clothing. Put cool water on the body. Place pieces of ice in areas where blood passageways are close to the skin. These include the back of the neck and under the arms.

Experts say it is important to know the danger signs of the medical disorders¹³ linked to hot weather. It is also important to know what to do if the signs appear -- in yourself or in someone else.

(MUSIC)

BOB DOUGHTY: Experts say water is important for many reasons. Between fifty-five and seventy-five percent of the body is water. Water in blood carries hormones¹⁴ and antibodies through the body. Water in urine carries away waste materials. Water is 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 liters of water a day to replace all the water lost in liquid wastes and perspiration. They say people should drink more than that in hot weather.

Experts say it is 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. During hot weather, cool liquids are best. Also, avoid sweet drinks and alcohol.

FAITH LAPIDUS: We need to add that doctors also say it is possible to drink too much water. Some people, for example, do this if they exercise hard during a heat wave. Experts with the Mayo Clinic say drinking too much water can cause hyponatremia. In this condition, the level of sodium¹⁵ in the blood falls too low.

The result is that the amount of water in the body increases. This causes cells to become larger. Mayo Clinic experts say the enlarged cells can cause a person to become sick or restless. They also can interfere¹⁶ with mental ability, make muscles weak and cause pain in the head. In a mild case, simply reducing fluids may be all that the person needs. But medical help is necessary if the condition is more severe.

Experts have suggestions for runners and others exercising or working hard in hot weather. They say drinking a sports drink with sodium in it can help prevent the condition.

BOB DOUGHTY: Doctors say actions other than drinking water 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 covering when 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 health problems linked to heat. They will prevent sickness, help you feel better and may even save your life.

(MUSIC)

FAITH LAPIDUS: This SCIENCE IN THE NEWS was written by Nancy Steinbach and Jerilyn Watson. Our producer was June Simms. I’m Faith Lapidus.

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

1 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。

2 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。

3 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

4 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。

5 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。

6 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。

7 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。

8 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。

9 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。

10 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。

11 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

12 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。

13 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》

14 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。

15 sodium   

n.（化）钠

参考例句：

• Out over the town the sodium lights were lit.在外面，全城的钠光灯都亮了。
• Common salt is a compound of sodium and chlorine.食盐是钠和氯的复合物。

16 interfere   

v.(in)干涉，干预；(with)妨碍，打扰

参考例句：

• If we interfere, it may do more harm than good.如果我们干预的话，可能弊多利少。
• When others interfere in the affair,it always makes troubles. 别人一卷入这一事件，棘手的事情就来了。