Many of our users have shared or expressed this concern. While this may be unavoidable, we suggest enabling your phone’s airplane mode before you go to bed to reduce incoming signals. You should also try to avoid placing your phone near your head while you sleep.
More information about radiofrequency energy and its relation to cancer can be found here: http://www.cancer.gov/cancertopics/causes-prevention/risk-factors/radiation/cell-phones-fact-sheet