Apple updates heat advisory for iPhone 3GS

Apple has released a revised technical support document that details the iPhone 3GS operating temperature zones.

David Martin
David Martin has more than 20 years of experience in the industry as a programmer, systems and business analyst, author, and consultant.
David Martin
2 min read

Last week, Apple revised a support document about iPhone temperature to include the iPhone 3GS. The June 25 document cautions iPhone 3G and iPhone 3GS users to operate their handsets within acceptable temperatures. It makes the following recommendations:

Recommended operating temperatures
Operate iPhone 3G and iPhone 3GS in a place where the temperature is between zero and 35 degrees Celsius (32 to 95 degrees Fahrenheit). Low or high-temperature conditions might temporarily shorten battery life or cause the device to temporarily stop working properly.

Recommended storage temperatures
Store iPhone 3G and iPhone 3GS in a place where the temperature is between -20 and 45 degrees Celsius (-4 to 113 degrees Fahrenheit). Don't leave the device in your car, because temperatures in parked cars can exceed this range.

Symptoms of overheating

  • iPhone will no longer charge
  • iPhone display will dim
  • Weaker cell signal
  • iPhone temperature warning screen appears (see below)

iPhone temperature warning screen pops up if the phone is overheating. Apple, Inc.

According to reader reports we've received, the iPhone's internal and ambient temperatures can spike when it's performing multiple functions simultaneously. Specific instances include using the iPhone while it's charging, using Wi-Fi during phone calls, and accessing data services during phone calls. Yet, we've also heard the iPhone can get warm during very long phone calls and during normal charging. Reports of discoloration on white iPhone 3GS models have been blamed on overheating.

Tips for keeping your iPhone cool

  • Some external cases--especially those that were designed before the iPhone was released and were not properly tested--can prevent heat from dissipating properly. Be especially wary of silicone covers, as they tend to act as insulators.
  • Power down various internal circuitry by putting the device in Airplane mode. Go to the Settings menu and slide Airplane Mode to On.
  • Don't leave the iPhone in a car on a hot day or in direct sunlight for extended amounts of time.
  • Use of certain applications like mapping and gaming for extended periods might lead to the iPhone overheating. Limit the length of these activities if possible.

Meanwhile, the iPhone user manual states:

"You cannot use iPhone while the temperature warning screen is displayed except to make an emergency call. If none of the above measures succeeds in lowering the internal temperature, iPhone automatically goes into a deep sleep mode until it cools. You cannot make an emergency call when iPhone is in this mode. Move iPhone to a cooler location and wait a few minutes before trying to use iPhone again."

A Fox News video covering the iPhone overheating issue can be viewed on Comcast's Web site. According to that video, your iPhone will shut down if the temperature inside the iPhone reaches 113 degrees.

While it is clear that overheating can happen, in all fairness, this is true of just about any electronic device. What's more, talking on a cell phone for a long period has caused other handsets to heat up, too. Is your iPhone 3GS overheating? Has the case shown any discoloring? Let us know in the comments.