Going by the reports that first made rounds at French site Nowhereelse.com, and circulated at US gadget sites like Engadget and Gizmodo, a few owners of the recently-launched Apple iPhone 3GS have complained about the overheating of the device.

The images that accompany the iPhone ‘overheating’ reports show an apparent discoloration of the especially the white phones, with their white-colored plastic backs turning brownish due to the handset’s supposedly high temperatures.

Even though a fairly small number of iPhone 3GS users have complained about the high temperatures of their handsets, component specialist Aaron Vronko, of Rapid Repair, told Wired.com that the ‘overheating’ issue could put at risk a large number of iPhones, considering the fact that over a million iPhone 3GSes were sold in the first weekend post-launch.

Vronko said the problem of overheating is possibly a result of some fault in the iPhones’ battery cells. He added that the complaints about overheating would likely prompt Apple to recall up to hundreds of thousands of units of iPhone 3GS.

Elaborating his point, Vronko said: “My guess is there’s going to be a whole lot of batteries affected because these iPhones are from very large production runs. If you have a problem in the design of a series of batteries, it’s probably going to be spread to tens of thousands, if not hundreds of thousands, and maybe more.”