Apple has issued a warning to iPhone 3GS customers that its spanking new mobile phone might be prone to over-heating.

The warning appears on an updated support document from Apple suggesting users should be careful about using the device.

Some owners have already reported that their white 3GS models are starting to turn pink or brown through overheating.

Apple suggests users should "Operate iPhone 3G and iPhone 3GS in a place where the temperature is between 0º and 35º C (32º to 95º F)", suggesting that "low- or high-temperature conditions might temporarily shorten battery life or cause the device to temporarily stop working properly".

Not much help when the UK is currently experiencing its worse heatwave for the last 3 years.

Apple recommends that users "Store iPhone 3G and iPhone 3GS in a place where the temperature is between -20º and 45º C (-4º to 113º F)," as well as suggesting users "Don’t leave the device in your car, because temperatures in parked cars can exceed this range".

The comments are a far cry from Nokia's testing procedures which bake its phones to a high 85 degrees Celsius heat, before freezing them in a -40 degrees Celsius cold freezer as part of the testing process.

Apple warns users, of the phone that has already sold 1 million units worldwide, that "If the interior temperature of the device exceeds normal operating temperatures, you may experience the following as it attempts to regulate its temperature:

- The device stops charging
- Display dims
- Weak cellular signal
- Temperature warning screen appears with the message "iPhone needs to cool down before you can use it"

However it doesn't mean that you've got a timebomb in your hand. The Apple support document states that the handset does comply to worldwide safety standards.

Are you experiencing issues with your iPhone 3GS? Let us know in the comments section.

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