https://www.cnet.com/news/how-long-can-your-phone-survive-in-a-polar-vortex/ > iPhones don't do well in extreme temperatures -- anything colder than 32 degrees Fahrenheit (or anything hotter than 95 degrees Fahrenheit), according to Apple. The company suggests shutting the phone off if it's colder than four degrees. > The phone's lithium-ion battery can stop discharging electricity at extremely cold temperatures.