Dr Hetzel trained at Royal Brompton and St Georges Hospitals London. He has been an NHS consultant Respiratory/ General physician since 1981; initially at University College and Whittington Hospitals, London and, since 1996, at Bristol Royal Infirmary. He has consulted at Bath Clinic since 1996. From 2006-10 he was Associate Postgradaute Dean, Severn Deanery, and Head of the Severn Postgraduate School of Medicine with overall responsibility for postgraduate training of all junior physicians in the Severn Region. He is a Senior Clinical Lecturer in Respiratory Medicine in the University of Bristol and an Admissions Tutor for Bristol Medical School.
He was formerly Chairman of the British Thoracic Society Research Committee, which promotes national lung research projects, and Founder Chairman of the BOLD (British Orphan Lung Disease) committee which promotes education and research into the treatment of rare lung diseases in the UK. He has also been Editor of the British Thoracic Society Website and newsletter.
From 2004-10 he was Royal College of Physicians Continuing Professional Development Adviser for South-West England (responsible for monititoring standards of educational meetings for consultant physicians) and was formerly the Royal College of Physicians Regional Adviser for South West England.
His research interests include the causes and treatment of night time asthma attacks, treatment of lung cancer by interventional bronchoscopy (laser, brachytherapy and stents) and the treatment of tumours of the trachea. He has produced over 100 peer reviewed publications on respiratory subjects. He is lead clinician for lung cancer for University Hospitals Bristol Foundation Trust. He is currently collaborating with basic scientists in the Department of Biochemistry, Bristol University, on development of new therapies for lung cancer. He has extensive experience in tuberculosis and runs the Avon TB clinic at Bristol Royal Infirmary; which is the major specialist clinic for tuberculosis treatment and prevention in the South West.