The iPhone 3G S could be turning out to be a hot item in more ways than one.

It was first reported on Nowhereelse ( a French website) via Engadget, by a user of a 16GB white iPhone 3GS who noticed that their iPhone got very hot while using the GPS and 3G of the phone. The only damage appeared to be that the back of the iPhone had a pink discoloration.

Then two PC World journalists had similar problems. Melissa J. Perenson from PC World reported in “Apple iPhone 3GS Overheating Reports” that her 16GB iPhone 3GS become very hot during use while being plugged in. David Coursey wrote of his problem in “Fahrenheit 113: Hot iPhone’s Tragic Number“.

So far Apple has not responded except for blaming hot weather or user negligence in their support article “Keeping iPhone 3G and iPhone 3GS within acceptable operating temperatures“. Notably, this article covers both the iPhone 3G and iPhone 3GS. It advises users not to leave the iPhone “in a car on a hot day” or “in direct sunlight for extended amounts of time“, and not to use “certain applications in hot conditions or direct sunlight for long periods of time, such as GPS tracking in a car on a sunny day or listening to music while in direct sunlight“.

So, is this just a general problem with the iPhone getting warm under high usage, or is there some hidden fault somewhere? What do you think?