Operating temperature Apple Watch is designed to work best in ambient temperatures between 32° and 95° F (0° and 35° C) and be stored in temperatures between -4° and 113° F (-20° and 45° C). Apple Watch can be damaged and battery life shortened if stored or operated outside of these temperature ranges. Avoid exposing Apple Watch to dramatic changes in temperature or humidity. If the interior temperature of Apple Watch exceeds normal operating temperatures (for example, in a hot car or in direct sunlight for extended periods of time), you may experience the following as it attempts to regulate its temperature:
Charging may slow or stop.
The display may dim.
A temperature warning screen may appear.
Some data transfer may be paused or delayed.
Some apps may close.
Important: You may not be able to use Apple Watch while the temperature warning screen is displayed. If Apple Watch cant regulate its internal temperature, it goes into Power Reserve or a deep sleep mode until it cools. Move Apple Watch to a cooler location out of direct sunlight and wait a few minutes before trying to use Apple Watch again. For more information, see support.apple.com/kb/HT6621.
Magnets Keep key cards and credit cards away from Apple Watch, the bands, the Apple Watch Magnetic Charging Cable, and the Apple Watch Magnetic Charging Case.