Fred Thompson Bowerbank was born at Penrith, Cumberland, England, on 30 April 1880, the son of Joseph Bowerbank, an ironmonger, and his wife, Mary Farrer. After attending Penrith High School he studied medicine at the University of Edinburgh, graduating MB, ChB in 1904. He worked for a while as assistant in a practice in Bury, Lancashire, then obtained a post as house physician at the Royal Free Hospital, London. He married Maud Pick on 21 February 1907 at Dunsby, Lincolnshire. Soon after their marriage the couple emigrated to New Zealand, where Bowerbank commenced practice in Newtown, Wellington. He was shortly recruited by Mother Mary Aubert as consulting physician to Our Lady's Home of Compassion and, in 1912, became visiting physician at Wellington Hospital.
He enlisted on the outbreak of the First World War and left for Egypt on 13 June 1915 with the 5th Reinforcements on the troopship Maunganui. He had been appointed officer commanding the medical division of No 2 New Zealand Stationary Hospital, and his wife joined him as a member of a Voluntary Aid Detachment at the end of 1915. After the evacuation of Gallipoli the hospital was reconstituted as No 1 New Zealand General Hospital and moved to Brockenhurst, England. While serving as deputy president of the Standing New Zealand Travelling Medical Board, Bowerbank acquired the Edinburgh MD in 1917 with a thesis on intestinal diseases in the NZEF. In January 1918 he moved to Étaples, France, as senior medical officer of the New Zealand Base Depot. By the end of the war he had been mentioned in dispatches four times and made an OBE. He had also earned a reputation for good medical judgement and administrative ability.
On his return to Wellington Bowerbank set about rebuilding his practice. He sat on medical boards, contributed to the official war history, and was appointed to the War Pensions Appeal Board. In 1924 he took study leave and gained his MRCP in Edinburgh. Thereafter he specialised in cardiology and metabolic diseases, becoming a pioneer of electrocardiography and the measurement of the basal metabolic rate. In 1928, with Clarence Meachen, he organised the first blood transfusion service in New Zealand.
Bowerbank was active in the New Zealand branch of the British Medical Association, serving as chairman of council from 1938 to 1940. He chaired the meeting in June 1937 that brought New Zealand physicians in with their Australian colleagues to form what became the Royal Australasian College of Physicians, and he was New Zealand vice president of the college from 1944 to 1946. He was also on the board of the Wellington Free Ambulance from 1934 to 1960.
As a member of the Territorial Force, Bowerbank had served as assistant director of medical services from 1929 to 1934. He then became director, with added responsibility from 1937 as principal medical officer of the fledgeling Royal New Zealand Air Force. He was largely responsible for keeping medical services going in the army during the depression. At the outbreak of the Second World War he was promoted to brigadier and appointed director general of medical services (army and air). For the next six years he unstintingly addressed matters as varied as the medical assessment of recruits and their diet on entering camp, the care of servicemen admitted to civilian hospitals, medical services for units in the field, and the post-war education of medical officers. He travelled often and widely to keep himself acquainted with rapidly changing conditions. In 1944 he was promoted to major general.
Bowerbank was knighted in 1946 and in the same year received the Dutch honour of grand officer of the Order of Orange-Nassau. He was also made a knight of the Order of St John. He went on to the retired list in March 1947.
Bowerbank published an autobiography, A doctor's story, in 1958. His interests, outside medicine and the army, included golf, gardening and walking. He was a Rotarian and a dominion president of Toc H. After the war he continued in his consulting practice as a cardiologist until 1960, when he suffered a stroke. He died four days later, on 25 August, in Wellington, survived by his wife. There were no children of the marriage.