Excessive heat and compact digital devices aren't strangers to each other; PDAs, cell phones and other portables often dissipate significant amounts of heat from their exteriors, sometimes causing discomfort for the handler.
The iPhone is no exception, with a number of users reporting uncomfortable heat generated by the device under some circumstances. More disconcerting, however, are reports that if the unit gets too hot, erratic behavior can ensue and the potential for component damage surfaces.
We've analyzed a series of reader reports and inferred the following:
When the iPhone gets extremely hot
- While charging
- When being used while charging
- While using Wi-Fi while on phone calls
- On very long phone calls (typical for most mobile phones)
In essence, it looks like performing multiple functions simultaneously on the iPhone (charging and talking on the phone or accessing data services; accessing data services and talking on the phone) can cause internal and ambient temperature to spike.
How to cool it off
- Ditch the case: Some cases, especially those designed before the iPhone was released an not properly tested with the device, can cause heat to not dissipate properly. In fact, some users have reported strange operation from the iPhone when using a heat-blocking case or cover. Be especially wary of silicone covers -- they tend to act as insulators.
- Put it in Airplane mode: Powering down various internal circuitry by putting the device in Airplane mode (Go to the Settings pane and slide Airplane Mode to On.
It also appears that some iPhones are more prone to excessive heat than others. If you're concerned that your unit's heat is abnormal, contact Apple.
Meanwhile, the iPhone user manual states:
"When you're using iPhone or charging the battery, it is normal for iPhone to get warm. The exterior of iPhone functions as a cooling surface that transfers heat from inside the unit to the cooler air outside."