Warnings have been issued to convertible drivers to take extra care this weekend as the UK’s heatwave is set to be interrupted by thunder and lightning.
Temperatures have reached 33C in some parts of the country this week – hotter than exotic holiday hotspots such as Barbados and Ibiza.
But forecaster says the prolonged sizzling temperatures will lead to a dramatic change on Saturday and Sunday, when violent electric storms will light up the sky in Milton Keynes and elsewhere.
This has led motoring experts to warn that while being in a car during lightning strikes is not an imminent danger to life, if you’re driving a soft top then you could be in peril.
Graham Conway, general manager of Select Car Leasing, says many drivers believe their rubbers tyres will keep them safe – but this is not true.
He added: “If a car is struck by lightning the metal structure acts like a Faraday cage. This means the electricity is sent around the outside of the vehicle and anything, or anyone, inside remains unharmed.
“But if you are driving a convertible, even if you have the roof up you don’t have a complete metal structure surrounding you and that means you could be in trouble.”
Faraday cages are named after English scientist Michael Faraday, who first observed the effect in 1836.
Lightning occurs when tiny ice particles in a storm cloud collide millions of times per second to create an electrical charge.
According to National Geographic, each bolt contains up to one billion volts of electricity and can heat the air to 5,000 degrees Fahrenheit – five times hotter than the surface of the sun.
There are an estimated 300,000 lightning strikes in the UK each year. On June 28, 2012, there were 64,000 strikes in a single 24-hour period.
The Tornado and Storm Research Organisation (TORRO) say there are on average two people killed and 30 people injured annually by the natural phenomenon in the UK.
The risk of being hit and killed by lightning is around one in 33 million.
Mr Conway added: “While being in a regular car is fairly safe if lightning strikes, there are still a number of things to consider.
“Make sure you are not touching any metal objects inside the car – including door handles, stereo dials and gear sticks.
“Also, if your vehicle is struck then remain inside until the storm has passed and even then take care touching anything metal outside the car for a period of time afterwards.
“As well as convertibles, fibreglass-bodied cars could be a potential risk because they don’t form the complete metal structure to act like a Faraday cage.
“And you obviously would not want to be on a motorbike in an electrical storm for the same reason.”