Record-setting heatwave cuts users off from overheating iPhones


26 Jul 2019

An overheating message appears on an iPhone. Image: Natalie Dewhurst/PA Media

A safety measure built into Apple’s iOS operating system stops users accessing their phone when it gets too hot.

As a widespread European heatwave sets record temperatures for July, it’s not just people who are feeling the heat but electronic devices too, with some iPhone users reporting that their handsets are struggling to deal with the weather.

With the mercury reaching 36.9 degrees Celsius at Heathrow Airport on Thursday afternoon (25 July), some iPhone owners have been taking to social media to report their encounters with a safety measure built into Apple’s iOS operating system. This feature stops users accessing their phone when it gets too hot.

Natalie Dewhurst, from Surrey in the UK, said her iPhone had displayed a temperature warning message when she left it out in the sun on Wednesday.

She told the PA news agency: “That’s my work mobile and if I position it near a window in my home office I often get reception … I got up to check it and it was so hot to touch so I put it near a fan and won’t be doing that again today!

“The warning has gone. It probably lasted about a half-hour until it cooled down … At the time it was around 34 degrees Celsius but the phone was in direct sunlight.”

What to do if your phone is too hot to function

On its support pages, Apple warns that iPhone handsets can become overheated if left in direct sunlight or in a car on a hot day.

Apple explains that if users see the temperature warning message, they should: “Turn [the handset] off, move it to a cooler environment and allow it to cool down.”

The warning message appears when the iPhone’s operating temperature is exceeded, which Apple says is an ambient temperature of between zero and 35 degrees Celsius. Users are encouraged to store the device in temperatures between minus 20 degrees Celsius and 45 degrees Celsius to avoid overheating or becoming too cold.

When users receive the warning message, they may be able to use the handset for emergency calls, but they will not be able to operate the phone.

Apple also warned users that using iPhones in “very hot conditions” could permanently shorten battery life.

Some iPhone devices may also cut down on a number of features to help regulate the temperature of a device that is starting to overheat, including slowing down or stopping charging, as well as phone performance on some graphics-heavy features, and disabling the camera flash.

– PA Media