iPhone Battery Risk Warning 

Apple has issued a warning to iPhone users about the dangers of practices like charging a phone under a blanket or pillow at night, risking overheating and posing a fire risk. 

Danger From Prolonged Heat Exposure 

In a wide ranging post on the iPhone user-guide section of Apple’s website, the company warns about the dangers of “prolonged heat exposure” in relation to skin contact with an iPhone, its adapter, or wireless charger. For example, Apple says that “sustained contact with warm surfaces for long periods of time may cause discomfort or injury” and ask users to “use common sense to avoid situations where your skin is in contact with a device, its power adapter, or a wireless charger when it’s operating or connected to a power source for long periods of time”. 

Don’t Sleep On Your Phone 

One specific example of a high-risk heat exposure situation given by Apple is “don’t sleep on a device, power adapter, or wireless charger, or place them under a blanket, pillow, or your body, when it’s connected to a power source. Keep your iPhone, the power adapter, and any wireless charger in a well-ventilated area when in use or charging.” 

Also, Apple warns iPhone users to “Avoid prolonged skin contact with the charging cable and connector when the charging cable is connected to a power source because it may cause discomfort or injury,” saying that “Sleeping or sitting on the charging cable or connector should be avoided.” 

What Could Happen? 

There have been many reports over the years of mobile phone-related accidents and incidents caused by overheating. For example, back in 2016, Samsung announced an (informal) recall of its Galaxy Note 7 phones following the discovery of a manufacturing defect in batteries which caused some phones to generate excessive heat and combust. There have also been high profile examples of phone batteries/chargers catching fire on aircraft, e.g. in January when a phone power-bank aboard an aircraft about to fly from Taoyuan International Airport spontaneously ignited. The fire filled the cabin with smoke, caused panic, there were 2 (minor) injuries, plus all 189 passengers and crew had to be to be evacuated. 

Apple Examples 

As for Apple devices specifically, there are many anecdotal and isolated incidents on the Internet where Apple iPhones reportedly caught fire due to issues with the battery or charger. A couple of examples which relate to overheating caused by/when covering the phone/charger include: 

– In 2017, a woman in Tuscon, Arizona reported that her iPhone 7 Plus exploded due to battery issues. The incident drew attention when she shared images of her burnt phone on social media. 

– In 2019, a young girl (an 11-year-old) in California reported that her iPhone 6 caught fire while she was lying on the bed and burned holes through her blanket. It was reported that after the incident, the girl said she didn’t plan to sleep with her phone next to her in future and suggested that the phone may have caught fire after overheating.

– In January this year, a family in Cincinatti posted photos and video captured by security cameras which allegedly showed an old iPhone 4 in their possession catching fire and exploding while charging. 

Lithium-Ion Batteries 

Although (as highlighted by Apple’s warning on its website whereby adapters and wireless chargers can be the source of fires) it’s long been known that Lithium-ion (Li-ion) phone batteries can pose a risk of overheating under certain circumstances. For example, known causes of overheating and fire in Li-ion batteries include excessive charging, using high current-drawing apps, exposure to high temperatures, using inferior quality (third party) chargers, old or degraded batteries, physical damage, software bugs, poor battery design or manufacturing, plus even exposure to direct sunlight. 

What Does This Mean For Your Business? 

For mobile manufacturers like Apple and others, identifying known risks to users is important for safety and compliance and the announcement and information on their website covers a wide range of potential risk areas.

However, the main point for users to remember in relation to covering phones while they’re charging (e.g. with pillows or bedcovers) or even leaving them on the bed, is that this should be avoided because an iPhone, its power adapter, and any wireless charger need to be used in a well-ventilated area when in use or charging.

There have been many stories circulating of phones overheating and the potential dangers of lithium-ion batteries in certain circumstances are widely known by most people, so it’s more a case of users taking (as Apple suggests) a common-sense approach, if possible, to minimise risks. That said, many people charge their phones overnight, and many have them on or near the bed when they fall asleep and there’s an argument that mobile phone manufacturers need to make batteries and charging safer as well as focusing on matters like the circular economy and the right to repair (and replace their own batteries).

Although other battery designs are being tested (e.g. stacked, graphene, solid state, and more) heat still appears to be the problem and until a battery design that is more efficient, effective, greener, affordable and safer can be introduced at scale, mobile phone users need to take responsibility and be aware of how best to mitigate the risks of overheating, thereby ensuring their own safety and the safety of others around them.