'He fired a gunshot when he saw me': Aussie GP's first day in a new job

In his day-to-day life, Dr John Parker is a GP in northern NSW. But he is also a medical mercenary who travels the world to confront humanitarian disasters.

Dr John Parker.

He has cared for people with Ebola and cholera and, more recently, the crew members quarantined on the ill-fated Ruby Princess.

Below is his colourful account of working in a major trauma centre