An iPhone Duo running hot is normal during setup, restores, updates, wireless charging and heavy apps, and it cools once the task ends. The phone is built to shed that heat, so heat that lingers or comes with a warning is worth acting on.
Apple gave the phone its own iPhone Duo vapor chamber and routed a graphite pipe through the hinge to move heat between the two halves. Even so, a phone left in a hot car or in direct sunlight can still overheat, which is where the steps below come in.
iPhone Duo Running Hot Is Normal During Setup, Updates and Heavy Apps
Graphics-heavy games, the camera and streaming high-quality video warm an iPhone the same way setup and restores do, and the phone cools once the activity ends.
If no temperature warning appears, you can keep using the phone. Use it between 0 and 35 degrees Celsius (32 to 95 degrees Fahrenheit), because very hot conditions can permanently shorten battery life.
Cool the iPhone Duo Down When It Gets Too Hot to Use
- Stop the heavy task, such as a game, GPS navigation, video recording or a long video call.
- Move the phone out of direct sunlight and out of a parked car, where temperatures can climb past safe limits.
- Unplug the charger and take the phone off any MagSafe charger so it is not heating itself further.
- Turn the iPhone Duo off if it keeps getting hotter, and let it cool in a shaded spot.
A Temperature Warning Means the iPhone Duo Is Protecting Itself
When the inside gets too hot, the phone slows charging or stops it, dims or blanks the display, weakens the cellular signal and can switch off the camera flash. Some apps run slower, with lower frame rates. During navigation you may see “Temperature: iPhone needs to cool down.” and the display turns off while audio directions carry on.
A Charging On Hold message on the Lock Screen means the phone is too hot to charge and will resume on its own once the temperature returns to normal. A full temperature warning screen means you should turn the phone off, move it somewhere cooler and wait. It may still make emergency calls while the warning is showing.
Protect the Battery From Repeated Heat
Keep the phone out of hot cars and strong sunlight, and avoid long GPS or gaming sessions in the heat. Heat shortens battery life permanently, so the habits that protect an iPhone battery from heat apply here too.
If the phone gets hot with nothing running, or a warning appears in normal conditions, restart it, update iOS and contact Apple Support if the heat keeps coming back.
