Apple is blaming a software bug and other issues tied to popular apps such as Instagram and Uber for causing its recently released iPhone 15 models to heat up and spark complaints about becoming too hot to handle.

The Cupertino, California, company said Saturday that it is working on an update to the iOS17 system that powers the iPhone 15 lineup to prevent the devices from becoming uncomfortably hot and is working with apps that are running in ways “causing them to overload the system.”

Instagram, owned by Meta Platforms, modified its social media app earlier this week to prevent it from heating up the device on the latest iPhone operating system.

Uber and other apps such as the video game Asphalt 9 are still in the process of rolling out their updates, Apple said. It didn’t specify a timeline for when its own software fix would be issued but said no safety issues should prevent iPhone 15 owners from using their devices while awaiting the update.

“We have identified a few conditions which can cause iPhone to run warmer than expected,” Apple in a short statement provided to The Associated Press after media reports detailed overheating complaints that are peppering online message boards.

The Wall Street Journal amplified the worries in a story citing the overheating problem in its own testing of the new iPhones, which went on sale a week ago.

It’s not unusual for new iPhones to get uncomfortably warm during the first few days of use or when they are being restored with backup information stored in the cloud — issues that Apple already flags for users. The devices also can get hot when using apps such as video games and augmented reality technology that require a lot of processing power, but the heating issues with the iPhone 15 models have gone beyond those typical situations.

In its acknowledgement, Apple stressed that the trouble isn’t related to the sleek titanium casing that houses the high-end iPhone 15 Pro and iPhone 15 Pro Max instead of the stainless steel used on older smartphones.

Apple also dismissed speculation that the overheating problem in the new models might be tied to a shift from its proprietary Lightning charging cable to the more widely used USB-C port that allowed it to comply with a mandate issued by European regulators.

Although Apple expressed confidence that the overheating issue can be quickly fixed with the upcoming software updates, the problem still could dampen sales of its marquee product at time when the company has faced three consecutive quarters of year-over-year declines in overall sales.

The downturn has affected iPhone sales, which fell by a combined 4% in the nine months covered by Apple’s past three fiscal quarters compared with a year earlier.

Apple is trying to pump up its sales in part by raising the starting price for its top-of-the-line iPhone 15 Pro Max to $1,200, an increase of $100, or 9%, from last year’s comparable model.

Investor worries about Apple’s uncharacteristic sales funk already have wiped out more than $300 billion in shareholder wealth since the company’s market value closed at $3 trillion for the first time in late June.