Doctors are warning about the risks of personal stereo equipment after a Vancouver man listening to an iPod was zapped by lightning while jogging in a thunderstorm.

The 37-year-old man's ordeal is published in this week's New England Journal of Medicine under the title: Thunderstorms and iPods — Not a Good iDea.

Eric Heffernan, Peter Munk, and Luck Louis from Vancouver General Hospital report in the journal that the man was jogging in the summer of 2005 when an adjacent tree was struck by lightning. The lightning then jumped to the jogger.

Witnesses reported that he was thrown approximately 2.4 metres from the tree, they said.

His eardrums were ruptured, his jaw fractured and he suffered first- and second-degree burns from his chest — where the device was strapped — up into his ear channels, along the trail of the iPod's earphones. He also had burns down his left leg and foot, where the electricity exited his body, blowing his sneaker to smithereens in the process.

What may have happened is what is known as a side flash — instead of the person being hit directly, the lightning jumps to a person from a nearby object. While the study didn't blame the device for attracting the lightning to the jogger, they did say the iPod made his injuries worse.

"Although the use of a device such as an iPod may not increase the chances of being struck by lightning, in this case, the combination of sweat and metal earphones directed the current to, and through, the patient's head," the doctors wrote.

Heffernan said in an interview with the Canadian Press that the man's experience ought to be a cautionary tale for anyone wearing earphones outdoors during a thunderstorm.

"Using things like this, a mobile phone or an iPod, there isn't actually an increased risk (of incurring a lightning injury)," he said from Vancouver. "But we just suggest that if you are unlucky enough to be hit by lightning while listening to anything with earphones, you may be more likely to do yourself some damage."

The man now has about 50 per cent hearing loss in both ears and wears two hearing aids, Heffernan said. He no longer plays in the church orchestra because of his hearing deficit.

"There are probably many notes he can't hear," Heffernan said.

Jogger suffered multiple injuries to ears, jaw

In addition to the perforated tympanic membranes (eardrums), the man suffered dislocation of the tiny bones in the middle ear known as the ossicles, which conduct sound to the cochlea of the inner ear.

Surgery was needed to patch the eardrums with grafts as well as to reset the jaw, which was dislocated from both joints, and to fix the bone, which was broken in four places. Heffernan said with this type of damage to the jaw, it's likely the man will develop arthritis in it, and at an early age.

Dr. Mary Ann Cooper, an expert on the effects of lightning on the body, said the iPod didn't draw the lightning to the man.

"Metal doesn't attract lightning and there is very little metal in iPods anyway," said Cooper, an emergency-room physician and medical professor at the University of Illinois in Chicago.

"But once electricity contacts the iPod, then the metal will conduct the electricity and can cause secondary burns, as this gentleman had to his chest underneath where the iPod was and up where the wires went up into his ears, and possibly even cause enough muscle contraction that either caused the jaw fracture or perhaps he fell forward onto his jaw."

With files from the Canadian Press