Some individuals have reported that they are able to feel a sensation on the phone side of their head while using their phone. There is no convincing evidence that exposure to portable phone RF radiation causes or is capable of causing cancer. The study involved looking at a total of 195,775 workers over a 20 year period. Robert W. Morgan, Michael A. Kelsh, Ke Zhao, et al. Supplementary issues with portable phones.
Portable phones can interfere with some electrical equipment.
Tests have also shown that ventilators and power wheel chairs may also be affected by some phones operating near these devices. There is a very rare theoretically possible health hazard mentioned in instruction manuals of some portable phones. It is the possibility for a portable phone when used in an explosive atmosphere to ignite an explosion. Explosive atmospheres could occur at a gasoline fueling station with the right percentage of gas and air mixture or in an area with air containing the correct amount of grain dust, or other explosive powder. In that atmosphere a spark from any source could ignite an explosion.