Your mobile device converts radio waves into electrical signals in order to send and receive your communications. At its peak (when the phone is turned on), power use ranges between 0.1 and 2 watts.

The radio waves that mobile devices rely on are at the non-ionising end of the electromagnetic spectrum. While a mobile device is used close to the human body, a small amount of energy from the radio waves is absorbed and this is converted into heat.

Scientific research has concluded that a temperature rise of no more than one degree Celsius is a safe level for the body. Our normal biological processes cool us down and prevent any significant temperature rise in our bodies.

The vast majority of experts, including the World Health Organization (WHO), agree that mobiles, operated in line with international guidelines, do not produce enough energy – and therefore heat – to cause long-term changes in the body.

WHO periodically reviews the science and is currently conducting another risk assessment of radio frequency electromagnetic fields. This is based on an extensive review of scientific studies published since their first review in 1993 and is due to be published in 2017–2018.