AppleCare warning: Overheating battery in 1st generation iPod nanos
Apple has released a knowledge base article describing battery overheating issues in 1st generation iPod nanos, suggesting users contact AppleCare immediately if they experience the problem.
Apple has determined that in very rare cases, batteries in the iPod nano (1st generation) sold between September 2005 and December 2006, may overheat and prevent the iPod nano from working and deform it.The first generation iPod nano had plastic faces, metal backs, and came in black and white.
Apple has received very few reports of such incidents (less than 0.001 percent) and the issue has been traced to a single battery supplier. There have been no reports of serious injuries or property damage. Additionally, there have been no reports of such incidents with any other iPod nano model.