It is permissible for one whose profession it is to save lives (such as a physician, nurse, or emergency medical technician) to work on Shabbat in order to save lives. It is permissible even for such a professional to use a telephone or pager to be alerted to their need for a life-saving act or to communicate life saving information, or to travel by any means necessary to the location where the potentially life-saving act will be performed. Some hospitals, such as Mount Sinai Hospital, have a designated Shabbat elevator for staff and visitors to use on those days; the elevators automatically stops on every floor, so that the observant persons do not have to push a floor button, which would be work.