If you are the owner of a first-generation iPod nano - sold between September 2005 and December 2006 - then you should stop using it and order a free replacement, Apple has said.
Apple has initiated an iPod nano (1st generation) Replacement Program for customers who bought one of the units, which "could overheat and pose a safety risk," according to Apple. Only the first-generation iPod nano is affected.
"This issue has been traced to a single battery supplier that produced batteries with a manufacturing defect. While the possibility of an incident is rare, the likelihood increases as the battery ages," Apple said.
The first-generation iPod nano (pictured) can be identified easily as it has a plastic front - either in black or white - and a silver metal back. Later iPod nanos have a metal back and front. If you are still unsure, though, you can take your device to an Apple Store or authorised reseller for identification.
On the iPod nano (1st generation) Replacement Program website you can fill in a form to get your replacement, which should arrive within six weeks. The serial number of your existing device will be checked and you should back up the iPod nano before returning it.
If you have a personalised iPod nano, you will receive a non-personalised replacement, Apple said. The new device is covered by a 90-day warranty.
The issue with the overheating batteries was known of since 2008, and Apple has offered replacements to customers who have come forward with complaints about overheating since then. The Japanese and South Korean governments have investigated the issue and Japan ordered Apple to publicise the replacement scheme on its Japanese website last year.
According to MacRumors, Apple began sending emails to customers who had bought a first-generation iPod nano over the weekend.