Studies have already been carried out into the effects of electromagnetic fields produced by electric cars and their effect on pacemakers. The good news is that EVs themselves do not produce a field that is a danger to humans fitted with implanted devices. While EVs do produce such fields they are well insulated to prevent interference with the vehicle's other electronic systems. What a further study did show was that the strongest fields were produced by chargers and their cables, but even in these circumstances the fields produced were not sufficient to put patients at risk. The European Heart Rhythm Association in Spain, who conducted the tests with high power public chargers, recommended that users with pacemakers or defibrillators do not place the charging cable directly over their implanted device.