There have been reports of iPhone 15 Pro phones exhibiting unusually warm temperatures following their release on September 22. Various public figures have presented theories as to why the iPhone 15 Pros are getting hot.
Some users reported temperatures of 48 °C using thermal cameras, and other users reported high temperatures while simply browsing through their home screens. Other iPhone 15 users reported no issues. Ming-Chi Kuo — a prominent Apple analyst theorized that the iPhone 15 Pro models are overheating due to compromises in the thermal system’s design.
This means that the new cooling system has been crippled, and Kuo says this could be caused by a reduced heat dissipation area and the fact that they switched frame of the Pro models from stainless steel to Titanium. The thermal conductivity of titanium is slightly less than stainless steel.
Why thermal conductivity matters: If a material has a lower thermal conductivity, it takes longer to dissipate heat and will therefore trap it. This causes temperatures to rise. However, the difference between titanium and stainless steel’s thermal conductivity is insignificant and not likely to be the cause of the problem.
If it was a hardware design flaw, all users would have been affected. Apple has stated that the high temperatures are caused by a bug in iOS 17 as well as updates to other apps, not a hardware issue. Apple has released an iOS update to address the issue — iOS 17.0.3.