<http://www.apple.com/ipodshuffle/specs.html> Operating temperature: 32° to 95° F (0° to 35° C) Nonoperating temperature: -4° to 113° F (-20° to 45° C) Relative humidity: 5% to 95% noncondensing Maximum operating altitude: 10,000 feet (3000 m) Yes, battery performance drops with lower temperatures. But worse: freezing can permanently damage your battery. Björn