All mobile phone users are being advised to keep their phones at a distance in order to reduce radiation exposure and other health risks associated with mobile phone use.
The California Department of Public Health issued the warning, after it was found that mobile phone use could cause different health issues.
The CDPH stated that different human health studies and experiments show that signals from mobile phones can be linked with headaches, low sperm count and certain types of cancer.
In a set of guidelines issued to mobile phone users, the CDPH advised people to use a headset when taking calls, send text messages instead of calling and avoid sleeping with your phone beside your bed.
It also urged people to carry phones in a backpack or briefcase, rather than a pocket, and to keep a distance from the phone when it is downloading or streaming content.
Speaking to CBS News, CDPH Director and State Public Health Officer Dr. Karen Smith said: "Although the science is still evolving, there are concerns among some public health professionals and members of the public regarding long-term, high use exposure to the energy emitted by cell phones."
She added: "We know that simple steps, such as not keeping your phone in your pocket and moving it away from your bed at night, can help reduce exposure for both children and adults."