They can be seen at public events from big shows and concerts, to charity fun runs and big sporting fixtures.
Everybody knows the work of the St John Ambulance Brigade.
And our archive pictures show them across the decades on the Fylde coast.
The St John Ambulance Brigade was formed nationally in 1887, but its origins go all the way back to 11th century Jerusalem, where the first Knights of St John set up a hospital to care for sick pilgrims.
The end of the 1890s saw more than 2,000 St John Ambulance volunteers offer medical assistance during the Boer Wars.
St John Ambulance volunteers performed their first duty for a major sporting event at the 1908 London Olympics, marking the beginning of a long-standing relationship between the charity and the sporting world.
The outbreak of the First World War in 1914 saw St John Ambulance join forces with the Red Cross, to form the Joint War Committee, providing medical care for war casualties in hospitals in England and overseas.
In the 1920s, the St John Ambulance Cadets were formed for girls and boys aged 11 to 18, offering first aid training to those who were too young to join an adult division.
At the Coronation of King George VI in 1937, St John Ambulance volunteers provided first aid treatment to 9,000 members of the public.
During the Second World War, the Joint War Committee once again came together, to provide voluntary first aid to the injured.
In 1948, the formation of the NHS altered the role of St John Ambulance who now support local ambulance trusts in times of need.
The 1970s were a period of unrest, and St John Ambulance volunteers provide first aid to the injured in a number of dangerous situations such as riots.
During the 1980s, when new first aid regulations were introduced for the workplace, St John Ambulance offered first aid at work training and has done ever since.