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Electric Shock First Aid – Surviving 240 Volts

FirstAidPro Danger High Voltage Sign

Table of Contents

Sharon McCulloch

Electricity is a mainstay in the modern home, with more product, gizmos, and gadgets plugging into our walls than ever before. But not all houses were built the same and for some Australian families the reality of dodgy wiring, faulty outlets, and outdated or obsolete safety switches can result in an increased risk to their safety. All this can mean you are in a situation where you need to provide first aid to someone, or need first aid yourself.

Fires caused by electrical faults, downed power lines, and exposed live wires. Electricity is potentially the most common threat found in Australian homes – that doesn’t crawl, fly, or slither that is!

(Which you can read more about here – FirstAidPro Articles)

What do you do when the very device you have used to enrol in your First Aid Course shocks you, or a loved one? Do YOU know?

Understanding exactly what electricity does to the human body and how you can help someone who has suffered an electrical shock can make all the difference when it happens to you.

Become a First Aid Pro, Save Lives! – Electric Shock First Aid Course 

What Happens During An Electric Shock?

An electrical shock occurs when an electrical current passes through your body.

Shocked child touching power lines

For example, touching two electrically charged points, such as a faulty extension cord, causes a live current to now pass directly through you as the electricity tries to leave your body through the path of least resistance – effectively turning yourself into an electrical circuit.

Another example of this happening can occur when the victim touches only one electrically charged point but is also in contact with the ground. What happens here is the circuit you have created within your body “earths out” and flows down into the ground searching for the path of least resistance. This is usually through the soles of your feet.

What Does An Electric Shock Do To Your Body?

FirstAidPro Purple Plasma Ball Electric Shock

A small amount of electricity may be too weak to feel or might cause nothing more than a faint tingling sensation. A more powerful shock can cause severe injury and even death. In many cases, the victim will experience a sudden uncomfortable sensation that will physically make them jolt – hence the name “shock”.

This is because your muscles are normally triggered by tiny electrical impulses travelling through your spinal cord. The electricity stimulates the nervous system in such a way that causes the muscle fibres to contract. As the electrical current pushes the action potential above the required threshold. This can cause your muscles to seize making it very difficult to let go or move to safety.

The specifics of your electrical shock can make a huge difference to the danger you face and the injuries you will receive, such as:

  • The voltage,
  • The amount of moisture present,
  • Your gender,
  • Perspiration,
  • If you have any facial or body piercings, and
  • Where the electricity entered and exited your body.

So while it’s not a good idea to grab a live wire with one hand – having the current flow down through your feet and into the earth.

Hands holding cables with blue electrical arc

It is far more dangerous if you are in contact with a wire in each hand – at which point the current flows up your arm, through your heart, and back out again. Leaving you in urgent need of CPR and immediate medical attention.

How Lethal Are Electric Shocks?

If someone dies as a result of an electric shock, it’s called electrocution.

FirstAidPro holding hand delivers CPR

This term is sometimes used to describe any electrical shock, but the term really only applies if the shock is fatal – it’s actually a combination of the words “electro” and “execution”.

Measured in Amperes or Amps for short, this is what makes electric shocks more or less deadly.

Depending on the Amp intensity of the current, the consequences caused by the electricity passing through your body will range in effect and severity.

Less than 1 mA (1 milliAmp) – Below 1mA, humans generally can’t sense an electrical current. So even if you’re technically getting “shocked”, you won’t feel it, and it won’t likely have any negative effect.

5 mA – Generally at this level of current you’ll experience a slight, sometimes painful, sensation. Typically, the only injuries likely to result from this are minor and easily treated.

6 mA – 16 mA – Known as a “Freezing current”, your muscle fibres will all contract simultaneously. Anything above this intensity is considered very dangerous. If you find yourself in this situation and have accidentally grabbed live wires, you will be unable to release your grip until the power is turned off. 

17 mA – 99 mA – At this point, there is a significant risk of death. This level of current will normally cause extreme pain and violent muscle contractions.

100 mA – 4,000 mA (4 Amps) – From this intensity, an electrical current passing through your body will cause life-threatening damage to your central nervous system and considerable damage to your heart muscle.

FirstAidPro unconscious SCA victim

Any electrical shock of this severity can trigger fibrillation, disrupting the rhythmic beating of your 

heart and stopping blood flow to the lungs and brain.

This is called a cardiac arrest and needs immediate CPR and AED intervention and paramedic assistance.

(Which you can read more about here – 

Volts, Amps And Ohms, Oh My!

FirstAidPro Exposed wires from wall electrical hazard

Perhaps you’re thinking “that’s great, but my electricity is all measured in volts, not in amps”. We know a car battery is 12V, and our power outlets are 240V, but how dangerous is that? How many amps will I get from a 240V wire? Will a car battery give me a heart attack or just a tingle?

The tricky thing is that it’s not easy to predict exactly how much current will flow through your body given a certain voltage.

The idea of voltage can be a little hard to understand, but despite what many people might think, it doesn’t actually mean “the amount of electricity coming out of my wall socket”. Voltage measures something called electrical potential. To know how much actual current will flow through you if you’re exposed to a certain voltage, you also need to know the resistance – and that’s hard to predict!

Water pressure and Electricity

These can be tricky concepts, so let’s use an analogy. Think of water in your pipes. The current is like the actual amount of water coming from the taps. The voltage is more like the water pressure in the pipes.

Good water pressure means a solid flow of water.
Bad water pressure and the water is coming out in a dribble, no matter how much you turn the tap.

Resistance is what limits the flow of the current, so it’s a little like the width of your water pipe.

Big pipe means more water, small narrow pipe, and you’re not going to get much water flowing unless there’s a whole lot of water pressure pushing the water through the pipes.

So low pressure, small pipe means a slow dribble of water. Low pressure, large pipe means more water, but still coming out slowly.
High pressure, small pipe means a fast stream of water, but only a tiny amount (like a water pistol).

But high pressure, large pipe??
That’s how you make a firehose!

Electricity is very similar. Low voltage (low pressure) and high resistance (small pipe) mean minimal electric current. High voltage, high resistance or low voltage, low resistance means more current but still relatively limited. But when you get high voltage and low resistance – that’s when things get dangerous.

Now… unfortunately, your insides are pretty good at conducting electricity – they have very low resistance. Particularly the wet bits – like your veins and arteries (which, of course, run straight back to your heart). Fortunately, under normal “dry” circumstances, your skin has excellent electrical resistance – meaning you’d need very high voltage to get much current flowing through your body. But wet skin, sweat, rain, and any number of other variables can make your skin a lot more conductive, meaning any electrical shock becomes a lot more harmful and life-threatening.

FirstAidPro High Voltage injury

It’s also worth knowing – if you’re exposed to “High Voltage” sources (500V or more), it can quickly damage your skin and make it less resistant, meaning that the already dangerous current gets stronger every second.

As a general rule, a 12V car battery might give you a jolt but probably won’t do serious harm (don’t try this at home, as that’s not always the case). A shock from a 240V wall plug can be lethal but isn’t always unlike touching a high voltage source such as fallen power lines which is often an instant death sentence.

What To Do After An Electric Shock?

If someone around you seems to have suffered an electrical shock (sometimes it’s hard to tell) the first thing to do is to check for danger – is the victim still being shocked?

It’s not unusual for someone to unknowingly grab a live wire and then be unable to let go, as the current causes their muscles to lock up. But you can’t help them if you get shocked yourself.

FirstAidPro Turning off power board for shock victim

If they’re still being shocked, there might be a simple way to break the connection – such as switching a device off or pulling out a plug. Even if they’re not in contact with the voltage source, you should still disconnect whatever caused the problem for safety.

Make sure you don’t touch the person or get shocked yourself. If there’s no easy way to turn off or unplug the electrical hazard, it might be a good idea to shut off the power at the switchboard for safety.

Once any risks are removed, you can assess the state of the victim and begin providing CPR and First Aid if required.

Electric Shock SymptomsUnconscious man with electric shock symptoms

Some minor shocks will give the person a jolt but have no other ill effects. However, there are various ways that electricity can affect the body, and not all of them are immediately apparent.

Some of the signs of a recent electrical shock include:

  • Loss of consciousness
  • Muscle spasms
  • Breathing difficulties (or no breathing)
  • Numbness / Tingling
  • Blunt force injuries (if the person was thrown back by the shock)
  • No pulse, or an erratic one
  • Headache
  • Vision / Hearing troubles
  • Burn marks where the electricity entered and exited the body
  • Seizures
  • Cardiac arrest
  • Burns around the mouth (in children – after chewing an electrical cord)

Electric Shock First Aid

When attempting to assist someone who has suffered an electrical shock, having someone with First Aid training can be pretty significant. Even a standard CPR course will teach valuable skills such as how to assess a situation and safely commence first aid (often called DRSABCD protocol), and how and when to perform Cardiopulmonary Resuscitation. FirstAidPro also provides a more specialised and in-depth CPR course for rescuing a victim from a low voltage electrical shock known as the Low Voltage Rescue Course.

How To Treat Electric Shock?FirstAidPro LVR and Electric shock first aid kit

If the person has received a relatively minor electrical shock – experiencing a jolt at the time but suffering from no other symptoms – they should generally be ok to carry on with their day. They’ve been lucky enough to get a shock with only a small amount of current.

If the shock has caused a burn, this can be treated like any other burn – running the area under cold water for 20 minutes and applying sterile gauze if needed.

If they start to show any of the other symptoms listed above, then it’s probably time for medical assistance.

When To Get Medical Assistance?FirstAidPro Heart ECG

If the person starts showing symptoms from the list above, it’s worth getting them to a doctor soon. Quite apart from the symptoms you’re seeing, electrical shocks can often have less visible effects, including things like nerve damage. If the effects seem significant (such as vision troubles or a seizure), consider visiting the local emergency department.

Even if the victim isn’t showing symptoms, but they’re either pregnant or have a history of cardiac issues, it’s worth getting checked out by a doctor following any electrical shock.

If the victim falls unconscious, doesn’t have a heartbeat, or can’t breathe, it’s time to immediately call 000 and then commence CPR first aid. If possible, find an Automated External Defibrillator (or AED) to commence defibrillation.

It might seem counterintuitive to try and revive someone from a severe electrical shock with another electrical shock. But it’s been well established for more than 100 years now – while a mild electrical shock across the heart (as low as 100 mA) can trigger cardiac arrest, a stronger shock can reset the system and allow it to restart again normally.

Article by Lochy Cupit

The content on this website offers general insights regarding health conditions and potential treatments. It is not intended as, and should not be construed as, medical advice. If you are facing a medical emergency, dial 000 immediately and follow the guidance provided.

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