It's summertime, which means storms, and you may wonder if it's safe to use your phone amid the bangs and crashes and flashes.
It is widely believed that you should not use your phone in a storm.
But is it true?
The Bureau of Meteorology (as reputable a source of information as you can get) advises its storm spotters: "If you are using a landline to phone through a report to the bureau, wait until the thunderstorm has passed, as you can receive a deadly electric shock or deafening sound blast when using a landline during a thunderstorm".
Wait until the thunderstorm has passed, as you can receive a deadly electric shock or deafening sound blast when using a landline during a thunderstorm.Bureau of Meteorology
"If an emergency occurs requiring the use of a landline during a thunderstorm, keep your call brief, don't touch any metal, brick or concrete, and don't stand barefoot on concrete or tiled floors," the bureau said.
"As long as you follow these procedures, it is safe to use a mobile or cordless phone indoors. However, a mobile or cordless phone should not be used outdoors during a thunderstorm, as holding any object with metallic components increases the risk of being struck by lightning."
What about sheltering from a storm in the car?
This is a good idea, or at least not as bad an idea as standing near the car or sheltering under a tree.
Do not stand in the open on high ground, particularly if you are under an umbrella. Do not go near long metal fences.
According to the National Weather Service (the American equivalent of the BoM), "the outer metal shell of hard-topped metal vehicles does provide protection to those inside a vehicle with the windows closed. Unfortunately though, the vehicle doesn't always fare so well".
Lightning looks for the easiest route to the ground and the car aerial may be that direct route. The metal of the car body will then conduct it to the ground, and around the people in the car (assuming they are not in contact with the metal body).
"The heat from a lightning strike is sufficient to partially melt the antenna of a vehicle and can cause what seems like a small explosion of sparks as tiny fragments of metal melt and burn.
"A portion of the discharge may find its way into the vehicle's electrical system and may damage or destroy electronic components, potentially leaving the car inoperable.
"The lightning may also find its way into the small defrosting wires that are embedded in rear windows causing the windows to shatter.
"Finally, it's very common for the lightning to destroy one or more tires as it passes through the steel belts to the ground.
"It's also possible for the lightning to ignite a fire which could destroy the vehicle."
On the subject of phones ...
We are told not to use or even be able to use phones in planes. Is this good advice? After all, it's likely that lots of people don't turn their phones to airplane mode when they leave them in their backpacks in the overhead locker or in checked-in luggage but no crashes result.
But Sven Bilen, Professor of Engineering Design, Electrical Engineering and Aerospace Engineering at Penn State University in the United States, still reckons that there is a "non-negligible risk that using your phone could interfere with critical systems on the plane".
"This is a particular issue on older aircraft," he said.
"Newer planes are designed to deal with the huge amount of electronics the flying public takes onto airplanes.
"Given how many new phones come on the market each year, it would be challenging to test how each and every model might interfere with the systems on each aircraft in the commercial fleet worldwide. So airplane manufacturers work to 'harden' the critical systems on their planes to make them less susceptible to interference from electronics."
But all the same, he recommends flight-safe mode.
Can you use phones at petrol stations?
You will have seen a warning sign at petrol stations saying that using your phone can cause an explosion.
BP says: "Don't use your mobile phone. If you drop your mobile phone, a spark can be produced when the batteries are knocked loose. This could be hazardous because of the flammable vapours produced by petrol products. If you need to make a call most service stations have a public pay phone."
But there's no evidence that there is a fire danger from using your phone.
The federal government's Australian Transport Safety Bureau looked at 243 incidents of fire at petrol stations and concluded: "None of these incidents occurred as a result of mobile phones igniting."
"The temperatures needed for static-ignited fires are much higher than the normal operating temperatures of mobile phone components. Hot surfaces would only be an ignition concern if there is a phone or battery malfunction. Mobile phones with non-genuine batteries may be at risk of over-heating and possibly generating a spark," the research found.
If there is a danger of a spark it may come more from your clothing when you go back to the car (say to look at the odometer reading) and rub against the seat, so generating static electricity.
But the bureau warns: "Mobile phones can lead to driver distraction during refueling."
And finally, why do we hang up a phone?
(For younger readers only): in ancient times, phones used to be attached to the wall by a cable.
When a call was over, the speaking and listening device would be hung up on a hook. This would end the call.
Time to hang up now.