I've actually wondered about this too. My brother-in-law was in the hospital not long ago, and when we visited him I saw a hospital worker on his cell phone in the hall. I have always thought that you shouldn't have your cell on in hospital, and I'm careful to turn mine off (although I also try not to use my cell in public as much as possible). But I have heard lately that some people are saying it really is safe. When my BIL was in the hospital, he had a phone in his room, but he had to pay at the nurses station to have the phone be able to dial out. He could receive calls, but not call anyone. They told him he was not allowed to use his cell phone. Yet, it was at this hospital that I saw the worker on his cell phone. Strikes me as odd....