1. Electrophysiology
a. What Causes Lightning
b. Types of Lightning
c. Types of Lightning Strikes
2. Injuries
a. Types of Injuries
b. First Aid and Victim Management
3. Prevention and Avoidance

1. Electrophysiology

a. What Causes Lightning. Lightning occurs most often on hot days when warm, moist air rises rapidly to great heights, forming dark clouds filled with static electricity. As a charge accumulates on the bottom of the cloud, an opposite charge develops on the top of the cloud and on the ground below the cloud. When the difference between charges reaches a potential greater than the ability of the air to insulate, lightning reaches out to equalize the difference.

Lightning is a "direct current" which may reach 200 million volts and 300,000 amps, with temperatures around 15,000 degrees F (Lightning can hit over 54,000 degrees F. This is five times greater than the surface of the Sun, although this is found in only one in a million strikes.) A bolt may reach out over a mile in front of a storm and move through a channel 3 inches wide. Bolts may be less than 300 feet up to 20 miles in length depending on the cloud's altitude from the ground. The speed of a downstroke may reach 100 -1000 miles per second. The speed of an upstroke can reach 87,000 miles per second.

Lightning strikes cause more than 1,000 injuries in the United States every year. Between 100 and 300 of these strikes are fatal. Lightning kills more people in the United States every year than all other natural disasters combined, usually between May and September, and those who die are usually working or playing outdoors.

b. Types of Lightning. Lightning comes in many forms. Streak lighting is the type most frequently seen. It is a single line or multiple line from cloud to ground. Forked lightning shows multiple channels. Ball lightning appears as a luminous globe that maneuvers like a flying saucer. Heat lightning, seen along horizons during hot weather, is the reflection of lightning occurring beyond the horizon. "St. Elmo's Fire" is a phenomenon that occurs when the electrical potential produces coronas from grounded objects. Lightning can travel from cloud-to-cloud, cloud-to-ground or ground-to-cloud.

c. Types of Lightning Strikes. Direct Strike. As the name implies, the bolt of lightning hits the victim directly. The victim is often near or in contact with a metal object (exterior frame back-pack, ice ax). Splash or Side Flash. The lightning strikes something more appealing than the human (trees, shelters), but "splashes" through the air to hit the victim. Ground Current. The charge radiates out from the strike point along the ground. This is lightning's most common way of harming people and the effects may result in many injuries from one strike. Blast Effect. The explosive expansion of air from the superheat of the lightning produces thunder, and can produce injuries in a victim who is thrown by the sudden movement of air.
2. Injuries

a. Types of Injuries. Cardiac Injuries. The current of lightning upsets and sometimes stops the natural rhythm of the heart. If the heart is healthy, it often restarts on its own. But it may fail to start up again because it is too damaged or suffering from a lack of oxygen. Respiratory Injuries. The muscles used for breathing have been shut down by the charge of electricity. Neurological Injuries. The victim is most often knocked unconscious by the charge, and some will suffer temporary paralysis, especially in the lower extremities. Seizures and/or the inability to remember what happened may result. Burns. It is not common to have serious skin and muscle burns after a lightning strike, but superficial burns are common. Blast Injuries. The impact of the blast can cause just about any trauma you can imagine: fractures, head injury, spinal injury, dislocations, chest and abdominal injuries. Other Trauma. Post-lightning victims complain most often of ringing in their ears, or loss of hearing, that usually resolves in hours to days without permanent damage. However, deafness is not impossible. Ears may bleed. Temporary loss of eyesight is not unusual, but blindness is rare. Victims often are bothered by insignificant nausea and vomiting for a brief time.

b. First Aid and Victim Management. Two factors make treatment of lightning strike victims unique. One is the triage of multiple victims and the other is the effectiveness of CPR. Generally, rescuers are taught to give priority to those still alive and let the dead stay dead. After a lightning strike, silent victims are very often recoverable and the moaning wounded can wait. Second, CPR done aggressively can bring many strike victims back to life since they are often physiologically sound, just shorted out.

Otherwise, the basic principals of first aid and CPR apply. When certain that the scene is safe, check the victim's ABC's. Humans do not store electrical charges, so they are safe to touch immediately. If the primary assessment is okay, go on to vital signs and the hands-on patient exam. Treat injuries as needed. Evacuate lightning strike victims even when they seem perfectly well. Problems can show up days later.

 

3. Prevention and Avoidance

Avoid likely target areas. Lightning does strike the same place over and over. Avoid places that look like they been hit before. The most dangerous places are on or near bodies of water. Lightning strikes in open areas. It will strike the tallest object. Move away from tall objects and metal objects.

Currents of electricity run like currents of water, from high to low. Stay out of ravines and other low spots that collect water. Deep dry caves are safe, but stay away from the entrance where lighting may jump the opening.

Thick growths of small trees of uniform height are usually safe. Spread out your group to provide more safety, making sure everyone can see everyone else. Crouch on your sleeping pad or some other non-conductive object and make your self as small as possible.

Crouch down with your arms wrapped around your knees, standing on the balls of your feet. This makes you the smallest target you can be with the least contact to the ground.

If you are in an open field, lie down in a hole. If you are in a field with only a few trees, crouch down in the open and keep a safe distance from the trees. This safe distance is usually given as a distance greater than the height of the nearest tree.

 

Do not make yourself a natural lightning rod by projecting yourself above the surrounding landscape.
In a boat, get as low as you can (below deck if possible) and, if the boat is a sail boat, stay away from the mast. If you are swimming get out of the water.

Get away from anything metal, including ATVs, bicycles, ski equipment, fishing rods, metal fences, farm equipment, and metal sheds.

If you feel an electric charge that causes your hair to stand on end or your skin to tingle, lightning may be about to strike you. Immediately drop in to the crouching position.
 

Prepared by Sandy Locke