57Hearing aidsSome digital wireless phones may interfere with somehearing aids. In the event of such interference, you maywish to consult your hearing aid manufacturer todiscuss alternatives.Other medical devicesIf you use any other personal medical devices, consultthe manufacturer of your device to determine if it isadequately shielded from external RF energy.Your physician may be able to assist you in obtainingthis information.Switch off your phone in health care facilities whenregulations posted in these areas instruct you to do so.VehiclesRF signals may affect improperly installed orinadequately shielded electronic systems in motorvehicles. Check with the manufacturer or itsrepresentative regarding your vehicle.You should also consult the manufacturer of anyequipment that has been added to your vehicle.Posted facilitiesSwitch off your phone in any facility where postednotices require you to do so.Potentially explosive environmentsSwitch off your phone when in any area with apotentially explosive atmosphere, and obey all signsand instructions. Sparks in such areas could cause anexplosion or fire resulting in bodily injury or even death.Users are advised to switch off the phone while at arefuelling point (service station). Users are reminded ofthe need to observe restrictions on the use of radioequipment in fuel depots (fuel storage and distributionareas), chemical plants, or where blasting operationsare in progress.