Apple has conceded that its new iPhone 3GS may be having some issues with regards to temperature its new smartphone can reach under normal circumstances. The company has been forced to issue a set of guidelines that will help users keep their handsets within a comfortable temperature range, thereby avoiding overheating problems. Apple's move comes after reports that white iPhones tend to turn pinkish brown quickly due to overheating.

The company says that the iPhone 3/3GS should be operated "in a place where the temperature is between 0º and 35º C". Failure to do so could shorten the battery life or cause the phone to temporarily stop working. Besides, the phone should be stored in places where "the temperature is between -20º and 45º C. Temperature in cars will often exceed the upper limit.

In addition, users should not use resource-hungry applications like streaming media or GPS over a long period as they put significant strain on the device's hardware. Failure to follow these guidelines could cause the display to dim, weaker cellular signal and finally a temperature warning may appear on the device's screen saying that the "iPhone needs to cool down before you can use it".

Moreover, it also looks like the new iPhone OS 3.0 update might cause older iPhone 2G and 3G to overheat.