Avoiding Electrifying Trail Experiences

What's more likely to occur, getting struck by lightning or hitting a Powerball jackpot?

According to the National Weather Service, the chance of being struck by lighting in a given year is less than 1 in a million (1/1,222,000), while the chance of hitting Powerball lottery about 1 in 292 million (1/292,000,000).

So, if you've ever bought a lottery ticket, "just in case, ya never know..." you should also consider safety around thunderstorms. 

Admittedly, the New England states have far less lightning strikes than the Southern and Midwest states, but they do occur, "and fatalities have occurred on Franconia Ridge and on Katahdin," and in Massachusetts. Beyond New England, you can find other stories of these unfortunate events happening to trail users.  I found this one article, by Bicycling.com about a mountain biker stuck and killed in Colorado that had an interesting way of ending the story, with a transition that essentially sounded like, "this was a tragic loss, but check out these rain coats..."

Anyway... to cover some basics,  thunder and lightning occur simultaneously.

The National Weather Service has great explanation:

Thunder is created when lightning passes through the air. The lightning discharge heats the air rapidly and causes it to expand. The temperature of the air in the lightning channel may reach as high as 50,000 degrees Fahrenheit, 5 times hotter than the surface of the sun. Immediately after the flash, the air cools and contracts quickly. This rapid expansion and contraction creates the sound wave that we hear as thunder.

Although a lightning discharge usually strikes just one spot on the ground, it travels many miles through the air. When you listen to thunder, you'll first hear the thunder created by that portion of the lightning channel that is nearest you. As you continue to listen, you'll hear the sound created from the portions of the channel farther and farther away. Typically, a sharp crack or click will indicate that the lightning channel passed nearby. If the thunder sounds more like a rumble, the lightning was at least several miles away. The loud boom that you sometimes hear is created by the main lightning channel as it reaches the ground.

Since you see lightning immediately and it takes the sound of thunder about 5 seconds to travel a mile, you can calculate the distance between you and the lightning. If you count the number of seconds between the flash of lightning and the sound of thunder, and then divide by 5, you'll get the distance in miles to the lightning: 5 seconds = 1 mile, 15 seconds = 3 miles, 0 seconds = very close.

So, lighting can be 50,000F degrees with millions of Volts and thousands of Amps, which, not surprisingly can kill or lead to permanent disability by direct strike, side splash, contact injury, or ground current. (side note, if, like me, you weren't sure about Volts and Amps, go here.)

  • Direct Strike: A direct lightning strike occurs when a person or object becomes the primary conductor for the electrical discharge. When lightning makes contact with a person, it travels through the body, following the path of least resistance, which is often the nervous system or blood vessels. This disrupts the body's electrical signals, affecting vital organs like the heart and brain, and can cause cardiac arrest, respiratory failure, or severe neurological damage. A direct strike is the most dangerous form of lightning strike and is often fatal.
  • Ground Current: Lightning can also cause casualties through ground current. When lightning strikes a tall object, like a tree or a building, the electrical energy spreads through the ground in a radial pattern. If a person is in close proximity to the strike point, the electrical current can travel through the ground and then up one leg and down the other. This can cause severe injuries or death by passing through vital organs.
  • Side Flash: Side flash, also known as side splash or side strike, occurs when lightning strikes an object, and some of the current jumps to a nearby person or object. If a person is standing too close to the main strike point, they can be affected by this "splash" of electrical energy and suffer injuries or death.
  • Contact Voltage: After a lightning strike, the electrical energy can electrify the ground and nearby objects. If a person touches a conductive object that has been charged by the lightning, such as a metal fence or pole, they can receive a deadly shock.

Cardiac arrest, neurologic damage, burns, blast trauma, and other injuries all classified as Keraunopathy can occur from lightning. 

So what can you do to be safe around lightning?

First is pay attention to the weather. In 2023, there's almost no excuse for not knowing that thunderstorms are predicted. Yes, surprise storms pop up, but with weather radar in our pockets, it's pretty easy to stay up to date on the weather. 

If you do get caught out in a storm, the first step is to try to find shelter, highlighted by the maxim, "when thunder roars, do indoors."

It will be hard to find truly safe shelter while on the trails. 

The Wilderness Medical Society, in their 2014 Practice Guidelines update say that "solitary trees, or open shelters (such as a picnic shelter, dugout, canopy, or lean-to) should be avoided because of the risk of side splash and ground current."

If you can make it to a metal topped car, that's good, just make sure that the windows are closed and you're not touching metal on the inside (seems like cars are mostly plastic inside anyway).

If you can't get to a car, "in a forest, a low area with small trees is safer than a clearing." And being around trees of similar size is safer than being near a solitary tree.  Avoid peaks and ridges. And while metal does not attract lightning, is an excellent conductor so metal objects, like a bike or trekking poles, should be placed away from you.

Now this little bit of advice brought me down a rabbit hole with no end. I took a recent Wilderness First Aid course that discussed all of these strategies and one of the tidbits of info that was shared was a video of a soccer game, in the Republic of Congo, in 1998, where lightning struck the field and several player on one team showed signs of injury. News actually reported that all 11 players on one team died, and one of the theories was that when the lightning struck, the electricity was conducted by the metal cleats used by one team, but not by the plastic cleats use by the other team. With that, I tried to determine if that was really true, because... I was wondering if cyclists should be advised to remove shoes with clipless cleats. I could never find definitive follow up from the initial news stories, and some posts talk about the incident, but I got nothing concrete.

So, I guess you can keep your shoes on, but the WMS Practice Guidelines for Lightning Injuries also recommends that groups separate by more than 20ft, and if it feels that a lightning strike is imminent (signs include a blue haze around objects or individuals, static electricity over hair or skin, an ozone smell, or a nearby crackling sound), assume the "lightning position."

WILDERNESS MEDICAL SOCIETY PRACTICE GUIDELINES https://www.wemjournal.org/article/S1080-6032%2814%2900274-9/pdf

Getting back to the fact that we estimate the distance of the storm by the time between the thunder and lightning, the current recommendations are to use the 30-30 rule. We said that for every five seconds between the first flash of lightning and the sound of thunder, the storm is about 1 mile away. So, if we wait until there are 30 seconds between the flash and the bang, we can estimate that the storm is about 6 miles away. And/or, stay sheltered for 30 minutes from the last sound of thunder. These are guidelines, but there is some disagreement, as the 30-second rule would suggest safety when the storm is 6 miles away, but lightning can strike as far as 10-12 miles from a storm

If you are ever out in a storm and someone you are with gets struck by lightning, you need to ensure your safety before acting. One tragedy can easily become two. You may need to get someone to a safer location before being able to help, and if a person does not have a pulse or is not breathing, you'll need to call 911 and start CPR.

Doing CPR on someone during an active storm while trying to protect yourself (and maybe others) and trying to contact rescue sounds like a horrible way to spend a summer afternoon, so my advice is to keep an eye on the weather and to change plans if needed. 

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