While we enjoy a balmy autumn, El Nino is having a devastating impact on the health of children in the Pacific Islands.

A pharmaceutical company, alongside Save the Children, has set up a mobile health unit in Vanuatu, where it says 28.5 percent of children are suffering stunting in growth from malnutrition.

The warmer weather is also helping the spread of disease.

GlaxoSmithKline New Zealand general manager Anna Stove has just got back from Tanna, in Vanuatu's south, and says it's devastating to see.

She said malnutrition remains one of the world's most serious health problems, and it's quite scary to see that it's on our doorstep.