Electricity for the 4-H Scientist Part 14

Once the rescue has been made and the victim is free of further danger, check to see if breathing has stopped. If so, start artificial respiration _immediately_ and send someone for a doctor.

Artificial respiration must be started as soon as possible after normal breathing ceases. _Most persons will die within 6 minutes or less if breathing stops completely unless they are given artificial respiration._ Precious minutes may have pa.s.sed before you get to the victim. Since the victim may be within seconds of death by the time you are able to touch his body, you should seek to obtain an air flow to and from the lungs _immediately_.

The victim may seem stiff as an effect of the current, so don't give up easily. Continue the procedure for several hours. If transportation is necessary, remember that there may be internal injury, fractures, or severe burns.

Mouth-To-Mouth Rescue Breathing

There are various effective ways to give artificial respiration, each with its advantages and disadvantages. The mouth-to-mouth method is recommended as a good one to master. It can be used on victims of drowning, suffocation, and asphyxiation, too. People have been known to save lives with less exposure to the correct procedure than you are getting by reading this. So, pay attention and remember what you read.

Step 1. Turn the victim on his back. Wipe out victim's mouth quickly.

Turn his head to the side. Use your fingers to get rid of mucus, food, sand, and other matter.

[Ill.u.s.tration: Head Position]

Step 2. Straighten victim's head and tilt back so that chin points up.

Push or pull his jaw up into jutting out position to keep his tongue from blocking air pa.s.sage. This position is essential for keeping the air pa.s.sage open throughout the procedure.

[Ill.u.s.tration: Push Jaw Up]

[Ill.u.s.tration: Pinch Nostrils]

Step 3. Take a deep breath, place your mouth tightly over victim's mouth, and pinch nostrils closed to prevent air leakage. For a baby, cover both nose and mouth tightly with your mouth. (Breathing through handkerchief or cloth placed over victim's mouth or nose will not greatly affect the exchange of air.)

[Ill.u.s.tration: Breathe]

Step 4. Breathe into victim's mouth or nose until you see his chest rise. (Air may be blown through victim's teeth, even though they may be clenched.)

Step 5. Remove your mouth and listen for the sound of returning air. If there is no air exchange, recheck jaw and head position. If you still do not get air exchange, turn victim on side and slap him on back between shoulder blades to dislodge matter that may be in throat. Again, wipe his mouth to remove foreign matter.

Step 6. Repeat breathing, removing mouth each time to allow air to escape. For an adult, breathe about 12 times per minute. For a child, take relatively shallow breaths, about 20 per minute. Continue until victim breathes for himself.

What Did You Learn? True or False

1. A broken arm should be splinted before artificial respiration is applied to a victim who is not breathing.

2. A person who has been severely shocked with an electric current should lie down.

3. A doctor should be called even though you successfully have revived a victim's breathing.

4. A fraction of an ampere through the human heart muscles can be fatal.

5. A copper wire would provide a better path than your body for stray currents, therefore all appliances should be grounded if possible.

6. Outside wires are never a hazard because they are covered with insulation when they are installed.

7. Cords need not be repaired until you can see bare wires.

8. Tuning in an AC radio while you are bathing is always dangerous, even though your hands are dry.

9. In an emergency, a broom is an acceptable tool for prying a victim off a high tension wire.

10. In mouth-to-mouth breathing, an adult's lungs should be filled 12 times per minute and a child's 20.

Demonstrations You Can Give

Show how to deal with an electrical first aid "problem" given to you by your leader.

For More Information

Ask your leader to have a first aid expert put on a demonstration. (Many industrial plants and power suppliers have such people.)

LESSON NO. B-12

Credit Points 3

HOW ELECTRICITY HEATS

In ancient times, people thought that heat was a material just as air is. They called it "caloric". When something got warm, they said, caloric flowed into it. When something cooled off, caloric flowed out of it. It did not bother them that they could not see caloric. They could not see air either!

Now we know that heat is not a material. It does not take up s.p.a.ce. It does not weigh anything. Instead, it is a form of energy. And when we say that heat is a form of energy, we mean that it can be used to do work.

What to Do

1. Make a simple resistance heater.

2. Make some popcorn by:

(a) conduction (b) convection (c) radiation

"Resistance" Makes Heat

There are at least four ways that electricity can make heat. The one that we'll cover here is _resistance_ heating. (The others are: _dielectric_ heating, where the lines of force of an electrostatic field pa.s.s through a non-conductive material and heat it; the _heat pump_, which is a refrigerator in reverse; and _electronic_ heating, which uses high frequency waves similar to radio waves to create high speed movement of the molecules or tiny particles which rub together to make heat.)

_Resistance_ heating occurs because every conductor of electricity opposes the flow of current through it. Some conductors resist more than others. When they do, a certain amount of warming takes place. The more resistance that is offered, the more heating there is.

Some materials, like silver, copper, and aluminum, offer little resistance. We say they are good conductors.

Other materials, like iron, offer more resistance. They are still conductors, but not as good as the others mentioned.