Apple has recalled adapter plugs sold with older iPhones amid concerns they might overheat. “In rare cases,” Apple warns, the 5W European USB power adapter “may overheat and pose a safety risk.” The adapter for European two-prong power sockets comes with the iPhone, and is also sold as a separate accessory. According to Apple, the only plugs with a problem are those that were sold with the iPhone 3GS, iPhone 4, and iPhone 4S between October 2009 and September 2012. A redesigned version comes with more recent phones. If you have one of the older, potentially defective adapters, Apple will swap it for one of the redesigned versions.