This is a known issue, and something Apple has an entire support page dedicated to.
The tech giant warns that prolonged exposure to cold conditions can have an effect on the expensive phone’s battery: ‘Using an iOS device in very cold conditions outside of its operating range might temporarily shorten battery life.’
In a nutshell, that’s because the plunging temperatures affect the lithium-ion batteries that iPhones (and most other smartphones) use for power.
Lithium-ion batteries create chemical reactions to produce energy and – when it’s cold – those reactions slow and, in some cases, stop entirely. That’s because the electrolyte liquid inside the battery crystallizes in the cold and the electricity can’t flow through it and into your phone.
The batteries will drain faster in cold weather and, at any rate, software inside the phone will shut it down if the temperature falls to low.
It’s not just cold weather, either. The same thing can happen if a phone gets too hot.
What is the right temperature for an iPhone?
According to Apple’s support page, the correct operating temperature for an iPhone is between 0º and 35º C.
The company explains that ‘low- or high-temperature conditions might cause the device to change its behavior to regulate its temperature.’
Of course, short-term exposure to sub-zero temperatures will have no immediate effect on the battery and Apple says that ‘battery life will return to normal when you bring the device back to higher ambient temperatures.’
The advice above is targeted towards iOS devices (iPhone, iPad and iPod touch) that are 4th generation and newer. If you’re using an older device than that and you’re battery keeps failing, it may be time to consider an upgrade.
How to keep your iPhone warm in cold weather
There are plenty of cases designed especially for keeping your expensive gadgetry cosy and warm in the depths of winter.
This one on Kickstarter claims to refract the heat from the phone back towards itself to keep it warm in chilly places.
But we’d suggest a more straightforward approach: tuck it securely into a coat pocket and try not to drop it in the snow too often.