All of the ceremonial county of Somerset is covered by the Avon and Somerset Constabulary, a police force which also covers Bristol and South Gloucestershire. The Devon and Somerset Fire and Rescue Service was formed in 2007 upon the merger of the Somerset Fire and Rescue Service with its neighbouring Devon service; it covers the area of Somerset County Council as well as the entire ceremonial county of Devon. The unitary districts of North Somerset and Bath & North East Somerset are instead covered by the Avon Fire and Rescue Service, a service which also covers Bristol and South Gloucestershire. The South Western Ambulance Service covers the entire South West of England, including all of Somerset; prior to February 2013 the unitary districts of Somerset came under the Great Western Ambulance Service, which merged into South Western. The Dorset and Somerset Air Ambulance is a charitable organisation based in the county.
What ambulance service covers the North West of England?