Operating Environment - Huawei U3900 User Manual

immediately before boarding. Using wireless devices in an
aircraft may disrupt wireless networks, present a hazard to
aircraft operation, or be illegal.

Operating environment

Avoid dusty, damp, or dirty environments. Avoid magnetic

fields. Using the device in these environments may result in
circuit malfunctions.
Do not use your device during thunderstorms to protect your

device against any danger caused by lightning.
Ideal operating temperatures are 0°C to 35°C. Ideal storage

temperatures are -20°C to 70°C. Extreme heat or cold may
damage your device or accessories.
Do not expose your device to direct sunlight (such as on a car

dashboard) for prolonged periods.
To protect your device or accessories from fire or electrical

shock hazards, avoid rain and moisture.
Keep the device away from sources of heat and fire, such as a

heater, microwave oven, stove, water heater, radiator, or
candle.
Do not place sharp metal objects, such as pins, near the

earpiece or speaker. The earpiece may attract these objects and
result in injury.
Stop using your device or applications for a while if the device

is overheated. If skin is exposed to an overheated device for an
extended period, low temperature burn symptoms, such as red
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