This is what Jim Little posted in another thread about having same problems with iphone 5:
I don't know how to link the post, so I'll just copy paste his post here:
"
After some further experimentation, there are serious cold weather performance issues with the iPhone 5 compared to prior generation iPhones. Starting at about 15 degrees farenheit (-10 celsius) the battery life of the iPhone rapidly deteriorates and the phone crashes and won't restart until warmed up.
I think there are a number of explanations for this:
- The performance of ALL batteries deteriorates in the cold. Batteries are a chemical reaction, and that reaction slows down in colder temperatures. Shelf life of batteries can be extended by keeping them cool, but you need to warm them up before you use them. That being said... I've skied for years with iPhones in the 1st-4th generation, and NEVER saw this problem with other iPhones.
- The iPhone 5 battery is thinner and has larger surface area than prior batteries. Larger surface area = faster cooling. Simple thermodynamics.
- The iPhone 5 shell is thin aluminum and has a larger surface area than the prior models. Aluminum has excellent heat transfer. This is why you can take a tin-foil wrapped potato out of a 350 degree oven and remove the tin foil with your bare fingers in seconds without burning yourself. The glass and plastic of the prior models did not cool down as quickly as the aluminum back of the iPhone 5.
- I do wonder if there are other components affected by cold, specifically processor, or perhaps expansion/contraction due to temperature change? Again, the iPhone 5 is so dramatically different than prior iPhone models I'm searching for other possible explanations.
The thermodynamic effects on the iPhone 5 are quite significantly different than the prior iPhone models in my experience. If I take it out of my warm inner pocket in 0 degree farenheit (-18 celsius) weather to snap a photo, it takes about 10-15 seconds for the phone to cool to the point where it will shut down. Too fast for me to snap pictures or video of my son or friends skiing.
Solution: Keep the iPhone 5 in a warm inner pocket. I put it in a zip lock baggie to help with moisture. I'm experimenting with heavier/thicker cases made of rubber or plastic to help slow down heat transfer. Once there are better iPhone 5 extended battery packs on the market (like the Mophie Juice Pack), I will probably get one of those for when I'm skiing or in the back country. I need my phone available, even in the cold weather, for emergencies. "
