Survival Skill: Lightning Safety
Now that the warm season of Spring and Summer is upon us, so is the season for thunder and lightning. The Wilderness Medical Society (WMS) reports that an estimated 400 lightning injuries occur annually. Still, the chance of death is quite low as the WMS reports, at roughly 40 deaths per year (as compared to approximately 70 flood-related deaths and 30 avalanche-related deaths which occur yearly).
Still, who really wants to be struck by lightning?!
Whether it is a Wilderness First Aid (WFA) or wilderness survival course, True North likes to believe that prevention is the best form of medicine. So, since many of us will be spending much time outdoors, especially hiking and camping along the Alleghenies or paddling the Three Rivers and surrounding waterways, and even quite a few of you will be leading groups outdoors and so will be responsible for their safety, I thought that I would share a portion of a recent research study conducted by the WMS that includes their recommendations.
If you aren’t familiar with the WMS, it is the leading source of protocols and guidelines for wilderness medicine and safety in the United States. I encourage you to learn more about it and check out their terrific resources.
Anyway, the safety portion of the article is below. You might find it a little long, but I hope worthwhile.
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BASIC SAFETY
No place is absolutely safe from lightning. However, individuals can choose safer places in an effort to reduce their risk of lightning strike. “When thunder roars, go indoors” is the currently recommended safety maxim of the National Weather Service. In essence, if one can hear thunder, then there is a risk of lightning strikes and one should seek shelter immediately. As substantial shelter is rarely available in the wilderness, hearing thunder in this setting should trigger an individual to immediately avoid or leave areas that are high risk for lightning strikes, such as ridgelines or summits, and to avoid tall objects such as ski lifts, cell phone towers, or isolated trees. One should observe for changing weather patterns that could indicate a developing thunderstorm: building cumulonimbus clouds, increasing winds, and darkening skies. Previous rules have relied on timing lightning flashes with thunder to estimate distance from an approaching storm. Such calculations may engender a false sense of security either from incorrect calculations or incorrect pairing of a given lightning flash with the correct thunderclap. Individuals should instead rely on observing signs of impending storms and seeking cover accordingly. Individuals should wait a minimum of 30 minutes after hearing the last thunderclap before resuming outdoor activity. Waiting 30 minutes should allow for the trailing edge of the thunderstorm to move the estimated 10 miles needed to establish an appropriate buffer zone.
SHELTER
There is no absolutely safe place from lightning—some locations are safer than others. When possible, shelter should be sought in the largest enclosed building available away from doors or windows. Another option is in a metal-topped vehicle with windows and doors closed; convertibles with fabric tops are not protective. As this option is markedly limited in the wilderness setting, this panel recommends seeking a sheltered area inside a deep cave, far into a dense forest, or in a deep ravine; these features represent a safer alternative than remaining in an open, exposed area. Shallow caves, 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. Tents do not provide adequate protection from lightning. When possible, the safest shelters are a building followed by a hard-top vehicle.
LIGHTNING POSITION
Take this position when lightning strike is imminent. Signs of imminent strike include a blue haze around objects or individuals (St. Elmo’s fire), static electricity over hair or skin, an ozone smell, or a nearby crackling sound. The lightning position involves sitting or crouching with knees and feet close together to create only one point of contact with the ground. If standing, have feet touching. If sitting, lift feet off the ground. Attempt to minimize the risk of ground current injury by insulating oneself from the ground; sit on a pack (remove any metal from the pack), a dry coiled rope, or a rolled foam sleeping pad. This is a strategy of last resort, as it is a difficult position to maintain for a long period of time, and should not be relied on as primary prevention but may reduce the risk of injury from an imminent lightning strike.
GROUP SAFETY
This panel recommends the separation of group members by greater than 20 feet to limit potential mass casualties, as lightning can jump up to 15 feet between objects. Although each individual should be aware of lightning safety, groups should develop a specific lightning safety plan. Such a plan accounts for local weather patterns, current weather forecast, local terrain, and predetermined available shelter and evacuation routes. A pre-established plan should mitigate the chaos of evacuating a crowd during a lightning storm.
LIGHTNING IN A MOUNTAIN ENVIRONMENT
The panel strongly recommends the avoidance of peaks and ridgelines in the afternoon as thunderstorms are most frequent during this time period. A common safety adage is “up by noon and down by 2” meaning that hikers and climbers should be off peaks and ridgelines by 2:00 PM. If caught in a thunderstorm, climbers should tie-off individually as lightning is able to conduct over wet climbing ropes and may affect both climber and belayer. Individuals should discard metal objects such as ski poles or mountaineering axes to avoid contact burns.
LIGHTNING IN A WATER ENVIRONMENT
This panel recommends that individuals exit the water and seek shelter expeditiously if caught swimming during a lightning storm. When rafting or kayaking, move to shore and away from the water’s edge as soon as possible. When boating, seek shelter below deck after locking off the helm. If no shelter is available below, tie into a lifeline.
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