Dr Alison Lyon was just three days into a volunteer position at a medical clinic on Vanuatu’s biggest island, Espiritu Santo, when an erupting volcano on a neighbouring island blanketed communities with ash and toxic fumes.

It was August 2018 and the NSW rural GP was on the front line of the disaster response as the entire population of Ambae Island, some 11,000 people, were evacuated by the government.