Electronics, especially those powered by lithium-ion batteries are not suited for temperature extremes. Apple claims iPhones are not suited for temperatures below 32 degrees. When exposed to below freezing temperatures, iPhones experience problems like shutting off, shortened battery life, display problems and even the glass shattering.
1) Keep it in your pocket
Keeping your phone in your pocket can protect it from cold temperatures and also help keep it warm from your body heat.
2) Use a special case
There are specialty cases that help keep your phone warm such as ClimateCase, Burton Antifreeze and Salt Cases.
3) Wait to charge your phone
Apple warns that charging iPhones in cold temperatures can damage the device.
4) Turn your phone off
In temperatures -4 to 113 degrees, make sure to turn your phone off to keep your device safe.