Lightning Safety Guide
In the United States, there is a roughly 1 in 3,000 chance of being struck by lightning within your lifetime, with around 10% of lightning strike victims dying as a result of their injuries. 400 Americans survive lightning strikes in the U.S. each year
Lightning is the second leading cause of death from natural disasters, behind only floods as the deadliest phenomenon in America. In the first 8 months of 2018, 17 Americans were killed by lightning. All but one of these was in the southeastern United States, and 82% were men.
According to the National Weather Service, 79% of all lightning deaths in the last ten years have been in June, July, or August. In summer, hotter weather brings more lightning storms at a time when people are more likely to be engaged in outdoor activities.
Despite the speed of a lightning strike, it is never the case that strikes happen from nowhere. Knowing what signs to look for, and how to be as safe as possible can hugely reduce your chances of being struck by lightning.
Although there are some common myths around lightning strikes, being aware of your surroundings, being informed about lightning, and not taking any unnecessary risks are all essential if you are to stay as safe as possible when lightning is around.
What is lightning and how is it dangerous?
Remarkably, there is not a scientific consensus on what causes lightning.
According to the National Geographic, some scientists have hypothesized that it is the presence of ice in a cloud that leads to lightning; positively charged ice crystals rise to the top of the cloud, and negatively charged crystal fall to the bottom. The large charge differentials that develop causes a discharge of current to the ground.
First and foremost, what makes lightning so dangerous is its sheer power. Lightning bolts carry, on average, 30,000 amps of charge and are 50,000 degrees Fahrenheit. Those who are not killed by lightning often experience severe burns and damage to the central nervous system.
Lightning strikes can be extremely unpredictable. Lightning can strike 10 miles away from the thunderstorm that produced it, and potentially even further.
That means that you can be standing under a blue sky and be in danger from lightning. Furthermore, lightning’s range means it can strike well in advance of, or behind, a thunderstorm. Put another way, you don’t have to be standing too near to a thunderstorm for it to be dangerous.
According to NOAA:
54% of lightning deaths occur in open fields (including ballparks and golf courses)
23% of deaths take place under trees
12% on the beach or on a boat
7% while operating farm equipment
This demonstrates that most individuals have little concept of how dangerous lightning can be, as well as the active steps they can take to minimize their risk of death. The best tools for being safe around lightning are knowledge, planning, and caution.
How are people struck by lightning?
When one thinks of being struck by lightning, it is usually of someone in an open field, being hit directly by a strike. However, there are actually more common ways of being injured or killed during a lightning storm. Knowing how you can be hurt is a critical step in helping you to avoid dangerous situations.
A direct strike is the simplest, if not the most common form of lightning strike A direct strike usually occurs when people are in open, exposed areas, and therefore form the highest point in the vicinity. A direct strike usually involves a flashover, where part of the current travels around the person’s skin.
This causes severe burns. More dangerous than the flashover, however, is the part of the current that travels through the victim’s body. If this passes through the cardiovascular or nervous systems, it can be deadly.
According to NOAA, “while the ability to survive any lightning strike is related to immediate medical attention, the amount of current moving through the body is also a factor.”
A side flash occurs when lightning hits a taller object near a victim. Most of the strike flows through the taller object, although a smaller portion of the current discharges ‘jumps’ into the victim. Side flashes usually take place when a victim has taken shelter from a storm or rain under a tree.
Side flashes can usually only move a foot or two laterally, although, under the broad canopy of a tree, the victim need not be directly next to the trunk for this to take place.
Ground current strikes are responsible for the highest number of lightning deaths to both humans and livestock. When lightning strikes an object, the current is dispersed through the ground immediately around the strike.
Effectively, the ground becomes electrified with a powerful current. This is common when lightning strikes man-made surfaces with conductive floors (such as garages), although can also take place in open fields.
Ground current enters the body at the point nearest the lightning strike and exits at the point further from the strike. Depending on the journey the current must take between these two points, it can enter the cardiovascular or nervous system and be fatal.
Contrary to popular thought, metal does not attract lightning; however, when metal is struck by lightning, it does provide an excellent conductor and can guide and transport current for long distances. Conduction can impact even those indoors, as current travels down electrical and phone wires.
According to NOAA: “anyone in contact with anything connected to metal wires, plumbing, or metal surfaces that extend outside is at risk.”
When lightning approaches the ground, many upward moving ‘streamers’ of charge actually move upwards to meet the strike. Only one of these streamers (usually) makes contact with the downward strike, connects the ground and the lightning, and causes the bright flash.
However, once the connection is made, all of the upward streamers discharge. Although streamer injuries are extremely rare, they can occur in proximity to a lightning strike.
What to do when there is a thunderstorm
If you are outdoors
The National Weather Service advises clearly and concisely ‘When Thunder Roars, Go Indoors!’ If you hear a thunderstorm, then the best course of action is to head inside a ‘substantial building or a hard-topped metal vehicle as fast as you can.’
Simply put, being indoors is the greatest way to decrease your chances of being hit by lightning.
If you are in charge of an outdoor activity, you are also in charge of planning a lightning contingency. If the weather forecast predicts lightning, then you should postpone your group activity.
As soon as you hear thunder, it’s time to take the group indoors, even if the storm seems like it’s a long distance away.
As stated above, lightning can strike 10 miles away from the thunderstorm. Wait until 30 minutes after you hear the last clap of thunder before resuming.
If you are outdoors and there are no shelter options for you, take the following steps:
Crouch down as low as possible. Don’t lie down, as you should aim to have as little of your body touching the floor as possible.
Avoid big, open spaces. In these spaces, you’re likely to be the highest point.
Get out of the water. If you are swimming in a lake or pool, get out immediately. If lightning strikes the surface, water is an excellent conductor.
Don’t stand by any isolated structure. Ground current strikes are likely when lightning strikes tall structures like trees or poles.
Don’t stand near any metal structure. Because of metal’s conductive properties, lightning can travel quickly and long distances down metal structures.
If you are with a group, spread out over a larger distance, but maintain visible contact with one another. This is the last resort if you can’t find shelter; it may increase the chance of any one individual being struck by lightning, but it greatly diminishes the chance of multiple casualties and guarantees that there will be help available if someone does get struck.
If you are indoors
Although the advice from the CDC and the National Weather Service is to head inside on the sound of thunder, you shouldn’t assume that you’re safe there. According to the CDC, one-third of lightning strike injuries occur indoors.
Take the following steps to stay as safe as possible when inside:
Avoid water (i.e. don’t take a bath or a shower, wash dishes, or wash your hands). Lightning can travel through plumbing, and water is an excellent conductor of electricity.
Avoid electronic equipment. This included computers. Lightning can travel down electrical cables from great distances, as well as through ‘radio and television reception systems.’
If lightning does strike your home, it can send a power surge through your electronics and can damage your equipment. The best way to protect your electronics during a storm is to unplug them.
A power surge can also travel through a home’s electric panel and burn and fuse the wiring. Installing a surge protection device for the electric panel will help prevent this.
Avoid any phone that is connected to a cord. Lightning can travel down telephone wires. Cordless or cell phones are safe to use.
Stand clear of any exterior windows or doors that may have metal components leading in from outside.
Stay off concrete floors and stand clear of concrete walls. As most concrete has metal rods running through it, concrete can conduct electricity very well and standing on a concrete floor puts you at risk of a ground current strike.
While basements are a common haven for people during bad weather, make sure to steer clear of any concrete basement flooring or unfinished walls. Also, when down there avoid going near any electrical or plumbing systems, such as washers, dryers, HVAC unit, and pipes.
Wait until 30 minutes after you hear the last thunderclap before returning outdoors.
What to do if someone is struck
If someone has been struck by lightning, they will need immediate first aid. Lightning strike victims do not retain an electrical charge, and therefore will not cause a discharge of electricity onto anyone providing first aid. NOAA states ‘Cardiac arrest is the immediate cause of death for those who die (after being struck by lightning).’
First aid can be the difference between life and death in these situations,
so take the following steps :
Survey the surroundings to determine if it is safe to approach before doing
so. Lightning may have weakened tree branches or other structures, so it is critical to be vigilant at all times.
Call for help; call 911 if you have access to a cell phone. It is safe to use a cell phone during a storm. Do not use a landline.
Begin CPR. Check the victim’s pulse. If there is none, compress the victim’s chest with your thumbs interlocked to the beat of ‘Staying Alive’ by the BeeGees.
If one is available, and you are confident with its use, use an Automatic External Defibrillator.
Move the victim to a safer place if at all possible. It is very unlikely that a lightning strike victim has broken bones that can cause paralysis, so moving can be a safer course of action than remaining. If the victim is bleeding or has broken bones do not move them.
Ultimately, although lightning can seem like an unexpected and random event, it can be anticipated. There are a lot of myths about lightning that may actually cause more harm than good. A lightning strike doesn’t always involve a direct strike from above the center of a thundercloud. Assuming that to be the case is extremely dangerous. Like any potential natural occurrence, understanding how and why lightning strikes make it much easier to stay safe.
In general, the safest course of action is to avoid being in situations where you are out in the open during a thunderstorm. Whether this involves paying attention to weather forecasts, or simply heading inside when you hear thunder, being indoors greatly reduces your chances of harm.
However, if this simply isn’t possible, then being smart, savvy, and prepared will stand you in good stead.
Have a plan in your head and where possible, stick to it. That will diminish the dangers of lightning and make you better prepared to deal with most eventualities.
References and Further Reading