Electrical Shock First Response

Why this matters

Electrical shock produces two kinds of casualty on residential jobs: the person who took the current, and the coworker who grabbed them to pull them off it. The second one is entirely preventable, and preventing it is the first thing this card teaches. The other thing it teaches is less intuitive: a person who took a real shock, shook it off and says they feel fine may still need to be in an emergency department within the hour, because the injury that kills after a shock is often a heart rhythm problem or internal damage that is not visible at the skin.

The guidance here follows the American Red Cross, the American Heart Association and OSHA. It is not training: hands-on first aid, CPR and AED certification is what makes a responder.

First: the person may still be part of the circuit

Do not touch someone who may still be in contact with the source. Current flows through their body into yours. A person locked onto a conductor often cannot let go, because alternating current makes the muscles of the hand clamp shut; the grip that holds them on is the shock itself. Separate the source from the person first, by the method that fits the source:

If the power cannot be found and shut off quickly, and only on ordinary household voltage, you may push or pull the person clear with a dry, nonconductive object: a dry wooden broom handle, a dry fiberglass ladder rail, a dry rope looped around a limb. Stand on something dry. This is a last resort for a 120/240 V source when the panel is out of reach. It is not an option for utility lines, service conductors or anything over household voltage, where the voltage can arc to you through the air or through a damp object, and where the only safe action is distance.

Water changes everything. A person who is in water, or lying on a wet slab with a cord or appliance in it, can energize the water around them. Do not step into the puddle until the power is off at the panel.

Once they are clear: the care that matters

When the source is off and the person is not touching anything energized:

• Check responsiveness and breathing. Tap and shout. If they do not respond and are not breathing normally, which includes occasional gasps, call 911, start CPR and send for the AED.
• Use the AED as soon as it arrives. The rhythm alternating current most often causes when it stops a heart, ventricular fibrillation, is exactly what an AED is designed to shock. A shock victim in cardiac arrest is one of the people an AED is most likely to help, and the AED is safe to use once the person is clear of the electrical source. See related: First Aid + AED on the Jobsite.
• Think about how they landed. A shock often throws a person or makes them fall from a ladder. A fall from height with neck or back pain, numbness or a blow to the head means do not move them. See related: Falls From Ladders and Possible Spinal Injury.
• Cover burns loosely with a clean, dry dressing. Electrical burns are often small at the skin and deep underneath, so their size is not their severity. Cooling with water is for heat burns; it is fine on a skin burn here once the power is off, but it is not the priority over breathing. See related: Burns: Thermal, Chemical, and Electrical.

Why "I feel fine" is not the end of it

Three things happen inside a shocked body that the person cannot feel:

1. The heart's rhythm can be disturbed. Current that crosses the chest, which it does on a hand-to-hand or hand-to-foot path, passes through the heart. It can cause an irregular rhythm immediately or, less commonly, later. A heart monitor (an ECG, electrocardiogram) is the way to find out.
2. Tissue along the path can be damaged. Current heats muscle, nerve and blood vessels along its route. The skin burn at the entry and exit points shows only where current crossed the skin, not what it did between them.
3. Damaged muscle can release proteins into the blood that strain the kidneys hours later.

So the rule this card commits to, in line with mainstream guidance: any shock where the current crossed the chest, left a burn, came from a source above household voltage, held the person on, or knocked them down or unconscious, gets medical evaluation the same day, even if the person feels fine. Call 911 rather than driving them when any of these is present: they lost consciousness even briefly, they have chest pain, palpitations or trouble breathing, they are confused, they have a burn, or the source was high voltage. Some guidance also flags a pregnant worker who takes any shock for evaluation, because current can affect the pregnancy when the mother feels nothing.

A brief tingle from a single finger to the same hand, with no burn, no chest symptoms and no fall, is lower risk. It still gets reported, and the person still stops work while the fault is found.

What responders and the ER need from you

The medical team will ask questions only the crew can answer. Write them on whatever is to hand and send it with the person. A note like this, filled in, takes two minutes:

  SHOCK NOTE FOR THE ER
  Time of shock:     09:41
  Source:            240 V line side, condenser
                     disconnect (breaker was on)
  Path:              left hand in, right hand on
                     metal cabinet (across chest)
  Held on?           No, let go at once
  Knocked down?      No.  Unconscious? No
  Burns seen:        small gray mark, left
                     fingertip
  Symptoms since:    shaky, says chest feels
                     "fluttery"
  Breaker opened at: 09:42, panel in garage

The path line is the one people leave out and the one the ER cares about most, because it tells them whether the heart was in the current path.

A worked case: the apprentice who wanted to keep working

A two-person crew is replacing a condenser. The apprentice opens the unit's pull-out disconnect, removes the pullout, and reaches in to loosen the line-side lugs with his left hand while his right hand rests on the metal cabinet. The line side of a disconnect stays live with the pullout removed, because it is fed straight from the breaker. He takes a shock through both arms, yanks back and lets go.

Scene. He is already clear, so there is nothing to separate. The lead still does not touch the unit, goes straight to the garage panel and opens the condenser breaker at 09:42, a minute after the shock. That is a scene action, not a repair: the fault that shocked one person is still there for the next.

Assessment. The apprentice is standing, talking, a little shaky. He says he is fine and wants to finish. The lead asks the questions in the note above and gets two answers that settle it: the path was left hand to right hand, across the chest, and he describes his chest as "fluttery". Either one alone meets the same-day evaluation rule. Together, with a heart symptom, they mean call 911 rather than drive, so the lead calls.

What happened next. Paramedics put him on a monitor in the driveway and took him in. He was observed for several hours and released. The lead filled in the note, wrote the incident up that afternoon and the shop's next huddle covered why line-side terminals are proved dead at the breaker, live-dead-live on a known source (NFPA 70E Article 120 (120.5 in the 2021 edition, renumbered in 2024), and OSHA's 29 CFR 1910.333 de-energizing practices), before anyone puts a hand in a disconnect.

Because he was observed and released rather than admitted, this was not a severe-injury report under 29 CFR 1904.39, which requires reporting an inpatient hospitalization to OSHA within 24 hours and a fatality within 8. Whether monitoring and observation alone make the case recordable on the 300 log is a 29 CFR 1904.7 question for whoever keeps the shop's log; diagnostic tests by themselves are not medical treatment under that section. See related: Accident and Incident Reporting SOP.

What changes the answer. If the apprentice had touched the line-side lug with one fingertip and the same hand's thumb, with no burn and no symptoms, the path would not have crossed the chest; he would still stop work and the shock would still be reported, but same-day evaluation would be a judgment call rather than the rule. If he had been unable to let go, the lead's first move would have been the breaker, not the apprentice, and if the panel were unknown, the only option on a 240 V source would be a dry nonconductive push. If he had collapsed, CPR and the AED would have started the moment the breaker was off.

The failure this case avoids. "He said he was fine" is the most common reason a shocked worker is not seen. Rhythm problems after a shock are uncommon, but when one appears the person is often alone in a van on the way to the next call.

References

• American Red Cross and American Heart Association, current first aid, CPR and AED guidelines on electrical injury.
• OSHA, electrical safety guidance and 29 CFR 1910.333 work practices for de-energizing before work.
• NFPA 70E Article 120 (120.5 in the 2021 edition, renumbered in 2024), for the live-dead-live verification of an electrically safe work condition.
• See related: The Shock That Seemed Fine; First Aid + AED on the Jobsite.
• See related: Burns: Thermal, Chemical, and Electrical; Rescuing Without Becoming the Second Victim.