October 15, 1998 transcript # 255-4
Subject(s): lightning
Title: Heart LightningDoctors have long been puzzled by cases where a seemingly healthy person is killed almost instantly by lightning, but shows none of the classic signs of a lightning strike, like burns or entrance and exit wounds. Now we may have an explanation. Hi, I'm Dave Thurlow and this is The Weather Notebook.
In Denver, two doctors and an electrical engineer have been working with the National Lightning Data Center to study these unexplained deaths. They think that lightning may kill a person by upsetting his or her heartbeat, even if it doesn't hit that person directly. Here's how it works.
The electric current in a lightning bolt sets up a magnetic field in the vicinity of the bolt. This field is much weaker than the main current of the strike, but it would still be enough to disturb the heart at a particular point in the heartbeat cycle. This weak point lasts only about a hundredth of a second between heartbeats. If lighting happens to strike at that instant within a few feet, then the researchers believe it could cause your heart to fibrillate. That's a chaotic, uncontrolled rhythm that can lead to heart failure in minutes.
It will take more research to prove that lightning can kill indirectly, but the basics of lightning safety remain the same. If you're in a lightning storm, take shelter in a building or a car, with the windows rolled up and avoid using electrical appliances until the storm has passed. If you're outdoors, avoid high places and open areas and stay away from natural lightning rods like a lone tree. Your heart will thank you for it.
Thanks today to contributing writer is Bob Henson, and for additional information on lightning safety, visit our website at weathernotebook.org. The Weather Notebook is a production of the Mount Washington Observatory, a non-profit organization in North Conway, New Hampshire. Support for our show comes from Subaru, the "Beauty of All-Wheel Drive," and from the National Science Foundation.