Subzero test shows that the Galaxy S II and cheapo Nokias are your best bet when chasing The Thing
Therefore they subjected a number of phones to subzero temperatures, and the results are pretty interesting. While we would expect entry level Nokias with their fairly small displays, and the build quality of the Finns to survive the lowest temperatures, it was pretty revealing to see the Samsung Galaxy S II being a close second, along with the Samsung Galaxy Xcover, which is a rugged phone by design.
iPhone 4S, for example, started going temperamental at 23 Farhenheit (-5 Celsius) and stopped working at 14 Farhenheit (-10 Celsius).
The issue is, of course, mostly with the phones' batteries rather than any other component, since the internal resistance increases immensely in low temps, so at some point the phone just reads the battery as empty and shuts down. The AMOLED display technology also proved superior to LCD in the freezing aspect, thanks to the simple facts that it uses organic diodes to emit light, while the liquid crystals tended to react slower and increase ghosting.