Funny to see this mentioned. I was recently out skiing and was using my phone to listen to music, as I used to do with my 3rd generation iPod. Moments ago I was lamenting to my colleague that while my phone's battery rapidly plummeted in the cold despite being insulated and close to my body (no way even remotely approaching freezing temperatures) my iPod never struggled to play tunes all day. In fact I never recall any noticeable difference in battery performance in cold temperatures despite daily use for years.

And yet my phone gets a bit chilly and gives up the ghost.

I use Bluetooth otherwise I'd have dug out the 3rd gen for the next ski day.