Lightning Safety

There are three different ways of being struck by lightning:

  1. Direct strike: the lightning hits you and goes to earth through you.
  2. Jumped: the lightning hits another object and jumps sideways to hit you.
  3. Ground strike: the lightning strikes the ground then travels through it hitting you on the way.

30/30 Rule

Research indicates that people are typically struck by lighting when they think they are safe from the peak effects of a thunderstorm. This is normally just before and just after a thunderstorm passes. When a thunderstorm is observed, think about its proximity, the possibility of a lightning strike and not the occurrence of rain. Using the following 30/30 rule is a good way of improving your level of personal safety during a thunderstorm. If the length between the lightning flash and the sound of thunder is 30 seconds in length or less (ie. less than 6 miles away) you should seek shelter immediately. Lightning has been estimated to travel over 10 miles through the air. Staying inside shelter is also advised until 30 minutes after the last thunder clap has been heard. By doing this you are reducing the risk of being struck at the beginning of the storm or from the trailing end of the storm as it passes.

Improving your safety during a thunder storm

  • Seek shelter inside a large building, preferably one with a lightning protection system installed.
  • Get inside a motor vehicle, (avoiding soft top convertibles). Cars are safer than standing outside due to the metal body of the car acting as a Faraday Cage conducting the electricity away from you before it is safety earthed to the ground through the tyres. Tyres are not good insulators when considering the enormous high voltage currents from a lightning strike.
  • Move away from wide open spaces or exposed hilltops.
  • If you are in water, get onto land or a boat as quickly as possible. The impurities in water can transmit the damaging effects from a lightning strike further away.
  • Move away from the open space of the shore or beach. Studies have shown that proximity to water is a common factor in lightning strikes.
  • If you are on a large enough boat or water vessel with a cabin, take shelter inside if you cannot make it to safety on shore. If you are in an open top boat, keep as low as possible in while making your way safely to land. Boats can also be fitted with lightning protection to safely disperse the energy from a lightning strike into the water.
  • If you are exposed to the elements with nowhere to shelter try to make yourself as small as possible by crouching down with your feet together, hands on knees and head tucked in. This technique keeps as much of you off the ground as possible as lightning will not necessary target the highest object in an area, but the object providing a path with the least resistant to ground. Try to do this in an area that provides the best protection for you, eg. golfers who cannot make it back to the club house should move away from their clubs and into shallow ground like a sand bunker. Do NOT lie down and do NOT stand in shallow water. If you feel your hair stand on end, drop into the position described above immediately. Your body contains a lot of moisture and is relatively a good conductor, it is therefore important to keep your feet together to minimize any current flow caused by radial energy from the strike zone passing through your body.
  • Do NOT stand under tall or isolated trees. It has been estimated that 25% of people struck by lightning were so as a result of taking shelter under these types of trees. Trees contain about 20% moisture content compared with humans who have a 65% moisture content. As lightning always takes the path of least resistance, you may become that path for any lightning jumps or radial energy from a strike.
  • Before doing any activity which may leave you in exposed situation eg. hill top walking, sailing, check the weather forecast. Try to avoid such activities if thunderstorms are predicted in the region of your activity.
  • If you know a thunderstorm is predicted, learn what places in your area offer you the best protection before it arrives.
  • When camping, avoid placing your tent at the highest point in the area, especially if thunderstorms are expected over night. If you are in a tent during a storm avoid touching or being close to tent poles if possible.
  • Be aware of objects that can attract or conduct a lightning strike, if possible avoid touching or using such items and move away if necessary.
    eg. inside: bathroom taps, central heating radiators, light switches, telephones, computer systems or any mains powered appliance.
    eg. outside: umbrellas, metal fences, golf clubs, bikes, fishing rods, sailing boat masts, antennas.
  • Be aware of any objects that can conduct electricity inside a building as these will provide an easy path for lightning to travel along on its way to ground. Building lightning protection systems are designed to migrate the immense current of a lightning strike away from a building’s internal systems. Even with lightning protection installed it is advised you avoid using any electrical system unnecessarily eg. your telephone (including mobiles), computers, television. Avoid touching any metal objects inside a building, eg. like metal pipe work, radiators, metal railing, unless your safety depends in it.
  • During a thunderstorm it is advised you do not use any corded phones next to your ear. Especially if you are in a building that does not have satisfactory lightning protection installed to protect its occupants and communication equipment.
  • In 2006 UK doctors in the “British Medical Journal” advised people to stay off mobile phones during a thunderstorm. When struck by lightning your skin’s high resistance will cause most of the charge to pass over the body in a process called “external flashover”. Any skin in contact with liquids or metal objects, like a mobile phone, will encourage the
    charge from a lightning strike to enter and pass through the body instead of traveling its exterior as an “external flashover”. As it travels through the body it causes major damage to internal organs on the way, more damage than occurs if it passes as an “external flashover”.

In Case of Emergency

If someone is hit by lightning, call emergency services immediately, as they will need help as soon as possible. Ensure your safety next by making sure the lightning strike has not placed you in any danger, or will put you in danger when you offer assistance. You will be less likely to help anyone if you also get injured yourself. If the only source of electricity was from the lightning strike you will not receive a electric shock from touching them. A lightning strike is not usually instantly fatal, however a victim’s heart or breathing (or both) may have stopped. A quick assessment and possible application of CPR may be required to save their life. People who are struck by lightning often suffer from severe burns and shock, both must be treated for with extreme care.