Emergency medical services (EMS), also known as ambulance services or paramedic services, are emergency services which treat illnesses and injuries that require an urgent medical response, providing out-of-hospital treatment and transport to definitive care. They may also be known as a first aid squad, FAST squad, emergency squad, rescue squad, ambulance squad, ambulance corps, life squad or by other initialisms such as EMAS or EMARS. In most places, the EMS can be summoned by members of the public (as well as medical facilities, other emergency services, businesses and authorities) via an emergency telephone number which puts them in contact with a control facility, which will then dispatch a suitable resource to deal with the situation. Ambulances are the primary vehicles for delivering EMS, though some also use cars, motorcycles, aircraft or boats. EMS agencies may also operate the non-emergency patient transport service, and some have units for technical rescue operations such as extrication, water rescue, and search and rescue. As a first resort, the EMS provide treatment on the scene to those in need of urgent medical care. If it is deemed necessary, they are tasked with transferring the patient to the next point of care. This is most likely an emergency department of a hospital. Historically, ambulances only transported patients to care, and this remains the case in parts of the developing world. The term "emergency medical service" was popularised when these services began to emphasise diagnosis and treatment at the scene. In some countries, a substantial portion of EMS calls do not result in a patient being taken to hospital. Training and qualification levels for members and employees of emergency medical services vary widely throughout the world. In some systems, members may be present who are qualified only to drive ambulances, with no medical training. In contrast, most systems have personnel who retain at least basic first aid certifications, such as basic life support (BLS). In English-speaking countries, they are known as emergency medical technicians (EMTs) and paramedics, with the latter having additional training such as advanced life support (ALS) skills. Physicians and nurses also provide pre-hospital care to varying degrees in different countries.