Teachers are warning of a gruelling winter ahead for children in poverty, as the cost-of-living crisis takes a major toll on struggling families, says KidsCan.

"They say it is affecting learning, with more children arriving hungry, others barefoot in freezing weather, and sickness spreading in overcrowded, unheated homes.," says a KidsCan spokesperson.

KidsCan has seen its waitlist double and has launched an urgent appeal to reach thousands of children who need support.

'Winter is always a miserable time of year for children in poverty, but this year is especially tough,” says KidsCan CEO Julie Chapman.

'With families' budgets more stretched than ever, they are rationing food, hot water, power and petrol. We're helping to feed and clothe more children than ever before, but we can't keep up with demand, and that's devastating.

'A child can't learn if they're cold or hungry – their brains are just in survival mode. So, this cost-of-living crisis has become a cost-of-learning crisis.

"From primary school children staying home due to petrol costs, to secondary students working huge hours to support their families, we should all be hugely worried about this. It's denying children the chance of a better future through education.”

Twenty-eight schools have applied for KidsCan support this year alone, as food inflation hits a 36-year high.

An increasing number of applications are coming from schools previously classified as decile five and six, who are seeing more need as working families struggle to make ends meet.

Staff at waitlist schools say they are feeding children themselves, says KidsCan.

Some families had only $20 left for food a week after paying rent and bills, so they were helping them access food banks. One principal was bringing in her own children's shoes so students could participate in subjects like technology where footwear was required.

'We've got kids who turn up in bare feet with just a shirt and shorts and it's freezing. They've been conditioned to accept that - they wouldn't know any different,” says one principal.

"Then they start becoming sick and it's just that ripple effect. We've had massive absentees with the flu.”

A social worker says the lack of food was having a real impact in the classroom.

'I don't think we realise how hunger affects our kids. Not just their behaviour, but their want to be here, their want and need to learn.”

KidsCan helps feed 55,000 children in 898 schools – more than a third of all schools nationwide – as well as 206 early childhood centres.

This term, it has brought 22 more schools into its programme, including four in Hawke's Bay, who were prioritised when the region was hard-hit by Cyclone Gabrielle. Thousands of children in 54 schools and 97 early childhood centres are still waiting for support.

The charity is itself under huge pressure from rising costs, with jackets 20 per cent more expensive than last year, and food staples like baked beans up by 39 per cent.

Donations are also dropping.

Monthly donors – who charities rely on for sustained support - are being forced to cancel to cope with the rising cost of living themselves. That means KidsCan is struggling to support as many new schools as initially planned this year.

KidsCan is calling for those who can afford to help support a child for just $15 a month, in a campaign that is supported by its Principal Partner, Meridian Energy.

To donate visit: www.kidscan.org.nz