The growing number of implantable cardioverter defibrillator (ICD) implants mean that a high number of patients carrying these devices are attended by physicians. In an attempt to simplify their management, articles have been published on the safety of applying magnets to the ICD in order to avoid the administration of shocks during surgery. However, performance of these procedures without the supervision of expert personnel can be accompanied by serious and potentially fatal complications. We report a case where the use of a clinic magnet over an ICD caused it to switch to "end of life" in the battery indicator and lose some antitachycardia therapies.