Lightning Science: Five Ways Lightning Strikes People
It is not always possible to know exactly how a victim has been struck, but here is a list of ways that lightning strikes its victims. Any of these types of strikes can be deadly. Immediate medical attention, including calling 911, starting CPR, and using an AED, may be critically important to keep the person alive until more advanced medical care arrives.
Direct Strike--A person struck directly by lightning becomes a part of the main lightning discharge channel. Most often, direct strikes occur to victims who are in open areas. Direct strikes are not as common as the other ways people are struck by lightning, but they are potentially the most deadly. In most direct strikes, a portion of the current moves along and just over the skin surface (called flashover) and a portion of the current moves through the body--usually through the cardiovascular and/or nervous systems. The heat produced when lightning moves over the skin can produce burns, but the current moving through the body is of greatest concern. 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.
Side Flash--A side flash (also called a side splash) occurs when lightning strikes a taller object near the victim and a portion of the current jumps from taller object to the victim. In essence, the person acts as a “short circuit” for some of energy in the lightning discharge. Side flashes generally occur when the victim is within a foot or two of the object that is struck. Most often, side flash victims have taken shelter under a tree to avoid rain or hail.
Ground Current--When lightning strikes a tree or other object, much of the energy travels outward from the strike in and along the ground surface. This is known as the ground current. Anyone outside near a lightning strike is potentially a victim of ground current. In addition, ground current can travels in garage floors with conductive materials. Because the ground current affects a much larger area than the other causes of lightning casualties, the ground current causes the most lightning deaths and injuries.
Ground current also kills many farm animals. Typically, the lightning enters the body at the contact point closest to the lightning strike, travels through the cardiovascular and/or nervous systems, and exits the body at the contact point farthest from the lightning. The greater the distance between contact points, the greater the potential for death or serious injury. Because large farm animals have a relatively large body-span, ground current from a nearby lightning strike is often fatal to livestock.
Conduction--Lightning can travel long distances in wires or other metal surfaces. Metal does not attract lightning, but it provides a path for the lightning to follow. Most indoor lightning casualties and some outdoor casualties are due to conduction. Whether inside or outside, anyone in contact with anything connected to metal wires, plumbing, or metal surfaces that extend outside is at risk. This includes anything that plugs into an electrical outlet, water faucets and showers, corded phones, and windows and doors.
Streamers--While not as common as the other types of lightning injuries, people caught in “streamers” are at risk of being killed or injured by lightning. Streamers develop as the downward-moving leader approaches the ground. Typically, only one of the streamers makes contact with the leader as it approaches the ground and provides the path for the bright return stroke; however, when the main channel discharges, so do all the other streamers in the area. If a person is part of one of these streamers, they could be killed or injured during the streamer discharge even though the lightning channel was not completed between the cloud and the upward streamer.
Lightning Safety Myths and Facts
Myth: Lightning never strikes the same place twice. Fact: Lightning often strikes the same place repeatedly, especially if it’s a tall, pointy, isolated object. The Empire State Building is hit nearly 100 times a year.
Myth: If it’s not raining or there aren’t clouds overhead, you’re safe from lightning. Fact: Lightning often strikes more than three miles from the center of the thunderstorm, far outside the rain or thunderstorm cloud. “Bolts from the blue” can strike 10-15 miles from the thunderstorm.
Myth: Rubber tires on a car protect you from lightning by insulating you from the ground. Fact: Most cars are safe from lightning, but it is the metal roof and metal sides that protect you, NOT the rubber tires. Remember, convertibles, motorcycles, bicycles, open-shelled outdoor recreational vehicles and cars with fiberglass shells offer no protection from lightning. When lightning strikes a vehicle, it goes through the metal frame into the ground. Don't lean on doors during a thunderstorm.
Myth: A lightning victim is electrified. If you touch them, you’ll be electrocuted. Fact: The human body does not store electricity. It is perfectly safe to touch a lightning victim to give them first aid. This is the most chilling of lightning Myths. Imagine if someone died because people were afraid to give CPR!
Myth: If outside in a thunderstorm, you should seek shelter under a tree to stay dry. Fact: Being underneath a tree is the second leading cause of lightning casualties. Better to get wet than fried!
Myth: If you are in a house, you are 100% safe from lightning. Fact: A house is a safe place to be during a thunderstorm as long as you avoid anything that conducts electricity. This means staying off corded phones, electrical appliances, wires, TV cables, computers, plumbing, metal doors and windows. Windows are hazardous for two reasons: wind generated during a thunderstorm can blow objects into the window, breaking it and causing glass to shatter and second, in older homes, in rare instances, lightning can come in cracks in the sides of windows.
Myth: If thunderstorms threaten while you are outside playing a game, it is okay to finish it before seeking shelter. Fact: Many lightning casualties occur because people do not seek shelter soon enough. No game is worth death or life-long injuries. Seek proper shelter immediately if you hear thunder. Adults are responsible for the safety of children.
Myth: Structures with metal, or metal on the body (jewelry, cell phones,Mp3 players, watches, etc), attract lightning. Fact: Height, pointy shape, and isolation are the dominant factors controlling where a lightning bolt will strike. The presence of metal makes absolutely no difference on where lightning strikes. Mountains are made of stone but get struck by lightning many times a year. When lightning threatens, take proper protective action immediately by seeking a safe shelter â€“ don’t waste time removing metal. While metal does not attract lightning, it does conduct it so stay away from metal fences, railing, bleachers, etc.
Myth: If trapped outside and lightning is about to strike, I should lie flat on the ground. Fact: Lying flat increases your chance of being affected by potentially deadly ground current. If you are caught outside in a thunderstorm, you keep moving toward a safe shelter.
For more information on Lightning Safety visit http://www.lightningsafety.noaa.gov/
Preparing For an Extended Power Outage
The storm may blow through in a day, but the lights may stay out for a week — or more. An extended power outage can mean shivering — or sweating — in the dark and, in some cases, can be a threat to your health and safety. The key to staying safe and comfortable during an extended power outage is preparation and knowing what to do when the lights go out. And stay out.
Before the lights go out
Every household should already have an emergency preparedness kit that will meet the needs of you and your family for three days. Much of what you need to make it through an extended power outage will be on hand with the gear on the checklist found at www.Ready.gov, the emergency preparedness Web site of the Federal Emergency Management Agency.
Northeast Utilities, New England’s largest utility system serving more than two million customers in three states, recommends putting together a “Lights Out Kit” that includes a flashlight for each family member, extra batteries, battery-powered radio and clock, bottled water, canned food, manual can opener, first aid kit and Sterno or a similar alcohol-based cooking fuel.
Because cordless phones won’t work when the power is out, you should include an old-fashioned corded phone in the “Lights Out Kit.”
Should anyone in the house use electrically powered life-support equipment or medical equipment, be sure to ask your physician about emergency battery backup systems.
Clearly label fuses and circuit breakers in your main electricity box. Make sure you know how to safely reset your circuit breaker or change fuses. Keep extra fuses on hand.
When the lights go out
Pull the plug on motor-driven appliances such as refrigerators and electronic gear such as computers and televisions to prevent damaging electrical overload when power is restored.
Keep the refrigerator and freezer doors closed as much as possible. You may want to your refrigerator and freezer to their coldest settings in advance of the storm. Just remember to reset the temperatures when the storm blows past. Food in the freezer can stay frozen for two to four days, according to the National Center for Home Food Preservation. During an extended power outage, you can use blocks of dry ice in the freezer.
Use extreme caution when using alternative heating or cooking sources. Never use camp stoves, charcoal-burning grills or propane/kerosene heaters indoors. Don’t use a gas stove or oven to heat the house. They all pose the risk of fire and carbon monoxide poisoning. More than 400 people a year die from accidental carbon monoxide poisoning, according to the Centers for Disease Control and Prevention. The symptoms of carbon monoxide poisoning include headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion.
If you use a portable generator, plug appliances into the generator. Connecting the generator directly to your home’s electrical system can send power up the line and kill a utility repairman working on the power lines. Generators produce deadly carbon monoxide, so be careful when placing it. Never refuel the generator while it is running.