Born in South Australia, Dr. Hewlett trained at Royal Adelaide Hospital in South Australia as a Resident Medical officer. He trained as a Senior Resident Medical officer with the Department of Internal Medicine, Repatriation General Hospital and as Medical Registrar at Royal Adelaide Hospital, Department of Internal Medicine and Subspecialties. At the University of Southern California,
Dr. Hewlett trained as a Barlow Fellow in Pulmonary Diseases and then served as Senior Clinical Pulmonary Fellow at the University of Colorado Medical Center. Dr. Hewlett received Board Certification in Internal Medicine in 1977 and in Pulmonary Diseases in 1978.
Dr. Hewlett has served as Visiting Specialist in Thoracic Medicine at Royal Adelaide Hospital, Visiting Specialist in Chest Disease at Repatriation General Hospital, and Visiting Chest Physician, Chest Clinic, at Commonwealth of Australia. At the University of California, Irvine Medical Center, Dr. Hewlett served as Assistant Professor of Medicine. He was also director of Medical Bronchoscopy as well as Director of Respiratory Intensive Care. He served as Medical Advisor for California Society of Respiratory Therapy Chapter 3 and for Planning Committee, Respiratory Therapy Program, Orange Coast College. At University of California, Irvine Medical Center, Dr. Hewlett served as an Associate Clinical Professor of Medicine. For fifteen years, as an outside attending physician, he was instrumental in teaching and advising pulmonary fellows and medical residents.
In addition to various publications and abstracts, Dr. Hewlett has been an invited lecturer to the American Association for Respiratory Therapy, the American College of Surgeons,the American Lung Association, Memorial Hospital Medical Center of Long Beach, Orange Coast College Respiratory Care Program, North American Medical/Dental Association, and Southern California Society of Gastroenterology. He is a member of the American College of Physicians and a Fellow of the College of Chest Physicians.
In his spare time, Dr. Hewlett enjoys golf and spending time with his grandson.