Why my cellphone gets hot without using

When does it get hot? is it charging when it gets hot? have you gotten any warnings on the screen that your device needs to cool down?

It can be normal for your iPhone to get hot, should never get to the point that its so hot that its burning or a fire hazard, usually if it does get to that point youll get an alert screen on the phone, here is some more information about the alert. If that does start happening take your iPhone in for service.

http://support.apple.com/kb/HT2101

You have an app that is stuck in a loop. If you have killed all of the apps in the Quick Launch ribbon it must be a built in app, probably Mail. Go into Settings and turn off your mail accounts. Then reboot the phone. If it cools down turn the mail accounts back on. If it doesn't run the battery all the way down until the phone shuts off, then charge to 100% with the wall charger.

If you still have the problem after these steps you may have a hardware problem, unless your phone is jailbroken. If it is all bets are off.

Operate iOS devices where the temperature is between 0º and 35º C (32º to 95º F). Low- or high-temperature conditions might temporarily shorten battery life or cause the device to alter its behavior to regulate its temperature.

Store the device where the temperature is between -20º and 45º C (-4º to 113º F). Don’t leave the device in your car, because temperatures in parked cars can exceed this range.

When using the device or charging the battery, it is normal for it to get warm. The exterior of the device functions as a cooling surface that transfers heat from inside the device to the cooler air outside.

Conditions and activities that may cause the device to alter performance and behavior include:

• Leaving the device in a car on a hot day.
• Leaving the device in direct sunlight for an extended period of time.
• Using certain features in hot conditions or direct sunlight for an extended period of time, such as GPS tracking or navigation in a car, or playing a graphics-intensive game.

If the interior temperature of the device exceeds the normal operating range, the device will protect its internal components by attempting to regulate its temperature. If this occurs, you may notice the following:

• The device stops charging.
• The display dims or goes black.
• In navigation:

  The device will present an alert and turn off the display:
  

  • Navigation will continue to provide audible turn-by-turn directions. When approaching a turn, the display will illuminate to guide you through the turn.
  • To return the device to normal operation, press the Home Button and slide to unlock. If the device has cooled down enough, you can continue normal usage.
  • Drive and ride safely. Give full attention to driving or riding and to the road.
• Cellular radios will enter a low-power state. The signal may weaken during this time.
• The camera flash is temporarily disabled.

If the device exceeds a certain temperature threshold, it will present a temperature warning screen similar to this:

To resume use of your device as quickly as possible, turn it off, move it to a cooler environment, and allow it to cool down.

Note (iPhone only): When this message appears, the device may still be able to make emergency calls.