iPhone 15 Pro overheating resolved: Thermal photos before and after iOS 17.0.3
ZDNET conducted thermal imaging tests on iPhone 15 Pro after Apple's iOS 17.0.3 update and has concluded the overheating issue with fast-charging appears to be resolved.
Apple rolled out its iOS 17.0.3 update on Wednesday with a release note that it "addresses an issue that may cause iPhone to run warmer than expected." ZDNET has tested this update and using a thermal camera has concluded that it has indeed resulted in the iPhone 15 Pro and Pro Max running cooler when fast-charging.
As widely reported since the arrival of iPhone 15 Pro on September 22, the iPhone 15 Pro and iPhone 15 Pro Max could get very warm when fast-charging or when using third-party apps such as Instagram, Uber, or Asphalt 9 that appeared to exacerbate a flaw in the iOS 17 software. Apple insisted that the overheating issue was related to a software bug and was not related to the new hardware or design in the iPhone 15 Pro models, which introduced a new titanium frame with an aluminum substructure to replace the stainless steel frame from the past several pro models.
In my testing with the iPhone 15 Pro and Pro Max, I experienced two overheating issues. The first and most major one was the iPhone 15 Pro Max getting very hot to the touch when fast-charging it with Apple's USB-C cable connected to a 35W charging brick. I was able to replicate this experience in another location using the same cable and charger. I used a thermal camera to measure the heat and found that the iPhone 15 Pro Max got as hot as 107.1 degrees Fahrenheit.
This was much hotter than other iPhone and Android phones, which typically maxed out at 85 to 95 degrees when fast-charging in my tests. The hottest any other phone got when testing in the same conditions was the Samsung Galaxy Fold 5, which got up to 98.7 degrees Fahrenheit.
The other overheating issue that I noted in my iPhone 15 Pro review appeared when jumping between the third-party camera app Halide and Apple's stock camera app while I was shooting a lot of photos outside on an 82-degree day. When I would swap back to the Apple camera app, it would very briefly display a message saying "iPhone needs to cool down" for 1-2 seconds before I could start using it again. Halide has also issued an update to its app that appears to have resolved that issue.