"It's gone crazy this week — the school holidays has an impact on it as well," the Salvation Army's Napier team leader Stephen Wallis said.
The Salvation Army's national director of community ministries, Jono Bell, said vulnerable people struggled for warmth, shelter and food over winter, which could often lead to health issues.
Those issues had led to the Salvation Army running its Winter Appeal which kicked off on July 8 and will run through till the end of the month.
It relies heavily on public donations to provide services to 120,000 people across the country each year.
"Substandard housing and poor heating often lead to sickness and people don't always get to a doctor when they should."
The latest Ministry of Health's Annual Data Explorer found that around one in seven adults (15 per cent) reported not visiting a GP due to cost.
"It's not only the fees that can be a barrier, but also transport costs to get there," Bell said.
"Even with free doctors' visits for children under 13, if there's no car, no petrol and no bus money, it's near impossible for some whānau."
Children from the most disadvantaged communities are twice as likely to end up in hospital for medical conditions and three times more likely to be hospitalised for respiratory conditions compared to those from the most advantaged communities, Ministry of Health figures show.
"We provide emergency help and services for long-term transformational change to disadvantaged communities, but we can't do it alone — we need public support."
The Salvation Army provides food parcels, budgeting advice, social work, youth development, and emergency and transitional housing to New Zealand's most vulnerable families and individuals, and specialist services include addictions support, emergency crisis support, reintegration services, senior support and chaplaincy support in courts and prisons.
"Our work will not let up in the coming months as people continue to struggle with keeping the house warm and food on the table, and we humbly ask people to give generously to our Winter Appeal so we can continue to fight poverty in New Zealand," Bell said.
* People can donate by visiting www.salvationarmy.org.nz/winter