With the cold weather, a rather odd problem appeared on my iPhone 4S – whenever I use the phone in weather below ~12 °C, it turns itself off and claims to be out of battery. This most often occurs when the battery is at 20-30 %, but isn't limited to that at all.
When it happens, I've found that rubbing the phone to heat it up helps, but that is a temporary fix, as it turns itself off again if exposed to cold again for a couple of minutes.
The fix has worked for quite a while, but it seems the phone can handle less and less cold - starting at about 10 minutes in -10 °C at 10 % battery left when it first happened, to about 3 minutes in 10 °C with 30 % battery. Therefore I have to ask – what can I do about it? I guess it will most likely have to be sent in for a replacement or repair, but I doubt this is covered by the phone's warranty (at least Apple's own)?