Red Cross opened a fully equipped field hospital in Cox’s Bazar and is providing the displaced people food, water, shelter and medical treatment.

Ms Collins will be based there from November 19 for four weeks and said the sheer scale of the humanitarian crisis has not been lost on her.

She helped during the Ebola outbreak in Africa, in the Solomon Islands last year during a dengue fever outbreak, and was part of the Red Cross disaster response team in Nepal after the 2015 earthquake.

But Bangladesh, a country she has never been to, will be her biggest challenge yet.

“The sheer number of people affected is something I’ve never seen before. It’s heartbreaking. Just the number of people arriving in camps with gunshot wounds and burns.

“Sixty per cent of those who are crossing over are women and children and that’s where my role as a nurse and midwife will be crucial.”

She said the Red Cross is doing a cholera vaccination campaign because the spread of water-borne diseases among the hungry, sick and the injured was a concern.

“My previous deployments have been as a nurse and a generalised team member but this time I’ll be providing midwifery care, which will be cool, as that’s my speciality.”

Ms Collins thanked the NDHB and her family for their support towards a worthy cause.

Red Cross estimates 604,000 Rohingya Muslims have crossed the border into Bangladesh since August 25 while hundreds more arrive every day, most of them on foot with only what they can carry. They are almost entirely dependent on humanitarian aid to survive.

In order to dramatically scale up response efforts, Red Cross urgently needs more than NZ$49 million to provide support to a further 200,000 people.

Ms Collins has urged people to donate generously so that more people can be helped.