SCIENCE IN THE NEWS in VOA Special English.
I'm Steve Ember
I'm Barbara Klein. This week, we tell
about health problems linked to extreme heat.
We also tell about what to do to prevent and treat these problems.
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.
storms and other natural events kill thousands of people every year. So does extreme heat. Experts say heat may be nature's deadliest
example, extreme heat was blamed for killing more than one hundred people in
India and Pakistan in two thousand seven.
Daytime temperatures rose to more than forty-five degrees Celsius in
some areas. On June eleventh, the
temperature in one desert town hit fifty-one degrees.
Experts say the total heat of a hot day
or several days can affect health.
Several hot days 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.
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
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 or high humidity. Humidity is the amount of water in the air.
several of these conditions are present at the same time, a person's body
temperature may rise above safe limits.
The person loses large amounts of body water and salt in
perspiration. Perspiration is one of
the body's defenses against heat. It is
how the body releases water to cool the skin.
people suffer only muscle pain as a result 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. Do not return to physical activity for a few
hours because more serious conditions could develop.
say some people face an increased danger from heat stress. Such persons 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 diabetes.
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.
heat stress can lead to a more serious problem called heat exhaustion. A person suffering from heat exhaustion
loses too much water through perspiration.
The person becomes dehydrated.
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.
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 suffering from 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.
exhaustion can develop quickly. But it
also can develop slowly, over a period of days. Doctors call this dehydration 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.
But if the problem continues for several days, the effects will be the
same as the usual kind of heat exhaustion.
Experts say that even a two percent drop
in the body's water supply can cause signs of dehydration, including problems
with memory and even simple mathematics.
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.
exhaustion can lead to heat stroke if it is not treated. Heat stroke is the most serious disorder
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 perspiring. The skin becomes
dry and very hot. A person may become
unconscious, not knowing what is happening.
say the body's tissues and organs begin to cook when its temperature is higher
than forty-two degrees Celsius.
Permanent brain damage and death may result. Immediate medical help is needed for someone with heat stroke.
Doctors say such treatment is necessary or the person could die before help
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.
say it is important to know the danger signs of the medical disorders linked to
hot weather. It is also important to
know what to do if the signs appear -- in yourself or in someone else.
Experts say water is important for many
health reasons. The body itself is
between fifty-five and seventy-five percent water. Water in blood carries hormones 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
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.
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.
hot weather, drinking cool liquids is best.
Cool drinks do more than just replace lost body water. They also help cool us faster than warm
liquids do. This is because they take
up more heat inside the body and carry it away faster.
Yet experts advise against drinking
sweet liquids in hot weather. The sugar
they contain slows the liquid from getting into the blood system. Tea and coffee also are not effective. Doctors also warn against alcoholic
drinks. Alcohol speeds the loss of body
water through liquid wastes.
say actions other than drinking water can protect against the heath dangers of
heat. Stay out of the sun, if
possible. Wear loose, light-weight 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.
say these simple steps can prevent the dangerous health problems linked to
heat. They will prevent sickness, help
you feel better and may one day even save your life.
SCIENCE IN THE NEWS program was written by Nancy Steinbach. Our producer was Brianna Blake. I'm Barbara Klein.
Steve Ember. You can read and listen to
this program on our Web site, voaspecialenglish.com. Join us again next week for more news about science
in Special English on the Voice of America.