No you do not need to shield your cell phone if its turned off. When the device is off it won't produce anything. If you have any other question or need hep with anything else please feel free to reach out to us.
If the phone is completely off, you shouldn't pick up any fields from it. If the phone is in airplane mode with WiFi/Bluetooth off, then magnetic fields can still be emitted. Keep the phone at least 3-5 feet away if you want to use it for an alarm clock in Airplane mode and with WiFi/Bluetooth off. At least then no radiofrequency (wireless) microwave radiation signals will be emitted. I use my phone as an alarm clock at times, but I keep the phone at least 3-5 feet away and always make sure Airplane mode is on and WiFi/Bluetooth are off. Some phones like to turn WiFi/Bluetooth on by themselves for some reason.
Customer support service by UserEcho