I use 3 smartphones and 2 laptops.full night all these items remain near my feet but since i had to put off alarms and all ,so usually last one hour of my sleep is with all 3 "switched on" smartphones quite near to my head. is it seriously harmful ?

There is no solid evidence that smartphones are harmful, even when they are in the proximity of the head, but I can tell you that having that many devices and screens near you while you're sleeping will affect the quality of your sleep, which can be detrimental to your health. If you can get rid of them while you were sleeping, you will be better off. Good luck.

I agree with Dr. S but I'm still concerned about your being exposure to a lot of radiation from those devices for so many hours close to your body. Many of us have not completely ruled out the incidence of brain glioblastoma and cell phone use.