WHAT MAKES US WARM?
MY thick,
warm clothes make me warm,” says some child.
No! Your thick, warm clothes
keep you warm. They do not make you warm.
Take a brisk run, and your blood will
flow faster and you will be warm very quickly.
On a cold day, the teamster claps
his hands and swings his arms to make his blood flow
quickly and warm him.
Every child knows that he is warm
inside; for if his fingers are cold, he puts them
into his mouth to warm them.
If you should put a little thermometer into your mouth, or
under your tongue, the mercury (mer’ku ry) would rise as high as it
does out of doors on a hot, summer day.
This would be the same in summer or
winter, in a warm country or a cold one, if you were
well and the work of your body was going on steadily.
WHERE DOES THIS HEAT COME FROM?
Some of the work which is all the
time going on inside your body, makes this heat.
The blood is thus warmed, and then
it carries the heat to every part of the body.
The faster the blood flows, the more heat it brings,
and the warmer we feel.
In children, the heart pumps from
eighty to ninety times a minute.
This is faster than it works in old
people, and this is one reason why children are generally
much warmer than old people.
But we are losing heat all the time.
You may breathe in cold air; but that
which you breathe out is warm. A great deal of
heat from your warm body is all the time passing off
through your skin, into the cooler air about you.
For this reason, a room full of people is much warmer
than the same room when empty.
CLOTHING.
We put on clothes to keep in the heat
which we already have, and to prevent the cold air
from reaching our skins and carrying off too much
heat in that way.
Most of you children are too young
to choose what clothes you will wear. Others
decide for you. You know, however, that woolen
under-garments keep you warm in winter, and that thick
boots and stockings should be worn in cold weather.
Thin dresses or boots may look pretty; but they are
not safe for winter wear, even at a party.
A healthy, happy child, dressed in
clothes which are suitable for the season, is pleasanter
to look at than one whose dress, though rich and handsome,
is not warm enough for health or comfort.
When you feel cold, take exercise,
if possible. This will make the hot blood flow
all through your body and warm it. If you can
not, you should put on more clothes, go to a warm
room, in some way get warm and keep warm, or the cold
will make you sick.
TAKING COLD.
If your skin is chilled, the tiny
mouths of the perspiration tubes are sometimes closed
and can not throw out the waste matter. Then,
if one part fails to do its work, other parts must
suffer. Perhaps the inside skin becomes inflamed,
or the throat and lungs, and you have a cold, or a
cough.
ALCOHOL AND COLD.
People used to think that nothing
would warm one so well on a cold day, as a glass of
whiskey, or other alcoholic drink.
It is true that, if a person drinks
a little alcohol, he will feel a burning in the throat,
and presently a glowing heat on the skin.
The alcohol has made the hot blood
rush into the tiny tubes near the skin, and he thinks
it has warmed him.
But if all this heat comes to the
skin, the cold air has a chance to carry away more
than usual. In a very little time, the drinker
will be colder than before. Perhaps he will not
know it; for the cheating alcohol will have deadened
his nerves so that they send no message to the brain.
Then he may not have sense enough to put on more clothing
and may freeze. He may even, if it is very cold,
freeze to death.
People, who have not been drinking
alcohol are sometimes frozen; but they would have
frozen much quicker if they had drunk it.
Horse-car drivers and omnibus drivers
have a hard time on a cold winter day. They are
often cheated into thinking that alcohol will keep
them warm; but doctors have learned that it is the
water-drinkers who hold out best against the cold.
Alcohol can not really keep a person warm.
All children are interested in stories
about Arctic explorers, whose ships get frozen into
great ice-fields, who travel on sledges drawn by dogs,
and sometimes live in Esquimau huts, and drink oil,
and eat walrus meat.
These men tell us that alcohol will
not keep them warm, and you know why.
The hunters and trappers in the snowy
regions of the Rocky Mountains say the same thing.
Alcohol not only can not keep them warm; but it lessens
their power to resist cold.
Many of you have heard about the Greely
party who were brought home from the Arctic seas,
after they had been starving and freezing for many
months.
There were twenty-six men in all.
Of these, nineteen died. Seven were found alive
by their rescuers; one of these died soon afterward.
The first man who died, was the only one of the party
who had ever been a drunkard.
Of the nineteen who died, all but
one used tobacco. Of the six now living, four
never used tobacco at all; and the other two, very
seldom.
The tobacco was no real help to them
in time of trouble. It had probably weakened
their stomachs, so that they could not make the best
use of such poor food as they had.
REVIEW QUESTIONS.
1.
Why do you wear thick clothes in cold weather?
2.
How can you prove that you are warm inside?
3.
What makes this heat?
4.
What carries this heat through your body?
5.
How rapidly does your heart beat?
6.
How are you losing heat all the time?
7.
How can you warm yourself without going to the
fire?
8.
Will alcohol make you warmer, or colder?
9.
How does it cheat you into thinking that you
will
be warmer for drinking it?
10.
What do the people who travel in very cold
countries,
tell us about the use of alcohol?
11.
How did tobacco affect the men who went to the
Arctic
seas with Lieutenant Greely?