The magnets inside iPad Smart Covers could switch off pacemakers if the findings of a 14-year-old's scientific experiments turn out to be true. While putting together a science fair project Gianna Chien made the discovery and should be presenting her findings to 8,000 doctors at a Heart Rythm Society meeting in Denver, Colorado.

The danger comes from the small magnets inside the iPad Smart Cover, which are used to keep it attached to the front of the tablet's display. If you were to fall asleep with the tablet lying on your chest, those magnets could interfere with a pacemaker and switch it off.

"The research offers a valuable warning for people with implanted defibrillators, which deliver an electric shock to restart a stopped heart," said John Day, head of heart-rythm services at the Intermountain Medical Center.

Apple's product guide for the device does say a minimum of six inches should be kept between tablet and pacemaker.

As many as 30 per cent of people tested in Chien's study said they were affected by the device. Defibrillators will switch back on after the magnet is removed but some need to be reactivated manually.

Hunter Skipworth

The baby of the Lint team, Hunter has been a tech fan since he bought his first MiniDisc..and what a waste of money that was. He began writing about electronics at the age of 16 and hasn't stopped since. Nowadays he fulfils his mobile phone and gaming obsession whilst attempting to distract people from his bizarre name. Regular meetings with the Gladiators crew see Hunter often returning to work battered and bruised. Considers himself a music obsessive, was once the most highly decorated scout in the country. Fan of trousers.