Do you shut down your cell phone when you sleep at night?

I usually shut down my cell phone when I sleep at night, because cell phone
radiation can harm my health . But, however, I have always worried whether or
not to shut down my phone at night, sometimes your friend or your boss who are
in urgent matter to inform you, but you have slept and shut down your phone,
then you can't get the information, and you or your company may get some loss .
So, I think whether or not to shut down your phone when you sleep is a bothersome
question . How do you deal with this problem? Share with us?