The term 'Halves of EMS' refers to the two branches of Emergency Medical Services (EMS): Emergency Medical Technicians (EMTs) and Paramedics. EMTs are trained to provide basic medical care and transportation for patients, while Paramedics are trained to provide advanced life support and can administer medications. The crossword solution for this term is ENS, which stands for Emergency Nursing Services. Emergency Nursing Services are a specialized branch of nursing that focuses on providing medical care in emergency situations.