How can I avoid being struck by lightning?

Kat - Thanks, Anne. And finally this week, Timothy Revell has been creating sparks with this Question of the Week...

Achmed - I was struck by lightning twice while I was on the telephone. On both occasions, my ears were ringing for days and the pain was excruciating. What I wish to know is, was I just unlucky or am I prone to attract lightning? Is there anything I can do to protect myself in the future?

Timothy - To find out the answer to Achmed's question, we spoke to John Jensenius, a lightning safety specialist from the American National Weather Service.

John - In the initial stages of a typical lightning flash, a charged channel develops downward from the thunderstorm cloud toward the ground. That channel is not attracted to anything. But approaches the ground blindly and tends to strike the tallest object in the immediate area. Once a connection is made with the ground, a brilliant flash that we call lightning occurs as charges are dispersed to the area surrounding the contact point.

Timothy - In other words, lightning happens when the electrical charge that is built up in clouds instantly discharges and hits the ground, a building or in two cases, Achmed. But is Achmed actually prone to being struck by lightning and was it something to do with him holding a phone.

John - You are not prone to being struck by lightning nor is your phone. Metal objects and wireless phones do not increase the chances of being struck. However, I should point out that the question of whether you're lucky or unlucky is debatable. It is certainly unfortunate that you were struck twice, but you are lucky to be alive and not seriously injured.

Timothy - So, every cloud has a silver lining, but what actually happens to your body when you get struck by lightning? We went to Dr. Hugh Matthews, a reader of sensory physiology at the University of Cambridge.

Hugh - If you get struck by lightning, the highest strength or voltage normally leads to most of the electric current flying past the surface of the body. Something called a flashover through the air as this means that the lightning can reach the ground more easily. The surrounding air gets hotter than the surface of the sun which causes a thermoacoustic blast wave. When this happens a longway away, we call it thunder, but when it happens right next to you, it can burst your eardrums or throw you to the ground, breaking bones.

Timothy - The fact that Achmed ears were ringing for days was due to this thermoacoustic blast wave even though most of the current doesn't flow through the body, it's still a serious problem.

Hugh - The biggest risk from lightning is disruption of the electrical signals which coordinate the heartbeat. This can lead to cardiac arrest. The electrical current can also stop you breathing by paralysing the chest muscles and disrupting the groups of nerve cells in the brain which control breathing rhythm. It's also common briefly to lose consciousness due to the immediate effects of the electric current on the brain.

Timothy - Assuming that you wouldn't like to lose consciousness from electrical currents on the brain, John told us what to do next time there is a storm brewing.

John - If you want to be safe, you'll need to get inside a substantial building or a hard top metal vehicle any time a thunderstorm is in the area. Remember, if you can hear thunder, you are close enough to be struck. When thunder roars, go indoors.

Timothy - Thank you John and Hugh for your illuminating answers and good luck Achmed in avoiding any future lightning strikes. Next week, we'll be leafing through the literature to find out the answer to this question which was written to us by Amelia from London.

Amelia - Why do leaves turn red in autumn and how do they know when it's time to drop?

Chris - And if you know the answer to Amelia's question, you can email chris@thenakedscientists.com, you can find us on Facebook or tweet @nakedscientists. There's also our web forum, thenakedscientists.com/forum. You can join the discussion there. That's it for this week. Thank you very much to Hannah Critchlow for her help with the production. Next week, we'll be continuing our future of humanity series. What will our cities look like in a hundred years' time? will people be living in the skies or underground, or we make our escape to the country? Thank you for listening and do join us at the same time next week. Goodbye.