Graduate of the National University of Ireland (University College Dublin) in 1969 and following internship undertook postgraduate training in anaesthesia in Bristol between 1971-75. He did a fellowship in paediatric critical care medicine at the Hospital for Sick Children between 1975-76 and a further year of research with Dr. Charles Bryan in the Division of Respiratory Physiology. Dr. Bohn was appointed as a staff physician in the Department of Critical Care Medicine in 1980. He was the Medical Director of the Extracorporeal Membrane Oxygenation (ECMO) Programme at The Hospital for Sick Children. In 2001, Dr. Bohn was appointed Chief of the Department of Critical Care Medicine and retired from the hospital in 2011. He is also past-president of the Pediatric Cardiac Intensive Care Society and founding chair of the Ontario Pediatric Critical Care Network. He served on the editorial board of Pediatric Critical Care Medicine, and is a regular contributor to both national and international symposia. In 2010 he took on the role of the Provincial Medical Director for CritiCall Ontario.