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After iPhone 15 overheating issues, Apple may improve hardware cooling in iPhone 16

Apple had to implement an iOS fix to solve iPhone 15 overheating problems – but a leaker today suggests that the company is looking to make a hardware change next year to improve passive cooling.

The report says that Apple may make two changes to improve cooling in next year’s iPhone 16 line-up …

iPhone 15 overheating issues

It wasn’t too long after the launch of the iPhone 15 line-up that a significant number of owners found their phones were overheating – with 9to5Mac’s Ian Zelbo one of those to report the problem.

The issue affected all four iPhone 15 models, with some reporting that their phones get too hot to even hold without a case. Thermal camera measurements measured temperatures as high as 116F.

We noted at the time that it’s not unusual to experience higher than normal temperatures in the first 24 hours or so of use, as the phone is busy carrying out background tasks like reinstalling apps and re-indexing, but the problem persisted for far longer than this. And while some experienced overheating during demanding tasks like gaming, others reported that it also occurred during more mundane tasks like browsing social media.

Apple denied hardware problems, issued software fix

Some sources suggested that hardware issues were responsible, in particular the switch from a stainless steel chassis to a titanium one in the Pro models.

Apple denied this, saying that it was a combination of a bug in iOS 17 and some third-party apps hammering the processor. In particular, said the company, titanium is actually better than stainless steel for heat dissipation.

The company promised a software fix, which it later issued as part of iOS 17.0.3, without impacting the performance of the phone.

Hardware cooling improvements for iPhone 16 suggested

Despite the iPhone maker’s insistence that there was no hardware issue, and the company’s subsequent vindication, Apple prototype collector Kosutami says that it is working on two hardware improvements for the iPhone 16 – both designed to improve passive cooling.

Apple is actively working on graphene thermal system of iPhone 16 Series to solve the heating problem existing before. And the battery of Pro series would change to metal shell, for the same reason.

The current heatsink is copper, and graphene offers around four times better thermal conductivity, while also reducing weight. That doesn’t necessarily imply a proportional improvement in real-life use, as the material can only absorb so much heat, but it would likely result in a worthwhile improvement

While many of the prototypes obtained by Kosutami are for older or abandoned products, they do also manage to obtain some for upcoming products, lending weight to the claim.

9to5Mac’s Take

Benchmarks are on Apple’s side when it comes to the claim that the iPhone 15 overheating problem was a software issue, not a hardware one. All the same, with better performance and lower weight, a switch from copper to graphene heatsink in the iPhone 16 is certainly plausible.

Photo: Toby Elliott/Unsplash

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Avatar for Ben Lovejoy Ben Lovejoy

Ben Lovejoy is a British technology writer and EU Editor for 9to5Mac. He’s known for his op-eds and diary pieces, exploring his experience of Apple products over time, for a more rounded review. He also writes fiction, with two technothriller novels, a couple of SF shorts and a rom-com!

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