Year 13 pupils Alice Sheehy, Anna Kirkwood, Matt Millikan, Nina Riddell, Sophie Pinto-Raetz and Matiu Gourlay will hunker down with sleeping bags, hot-water bottles, puffa jackets, cellphones, barley sugars and juice for this year's World Vision 40 Hour Famine appeal.
They enter the 2m-high, 1.8m-wide, 1.8m-long fence and tarpaulin cage at 6pm and will stay there until 10am on Sunday.
The pupils will be supported by co-ordinating teacher Katie Tomkins, parents, police and the X-It Youth Centre.
Money from the donations box will be emptied regularly.
Miss Pinto-Raetz said she had grown up with her mother telling her to eat all her food gratefully as there were far less fortunate children in the world.
"One day she showed me a picture of these starving children and I thought, `I've had it pretty lucky in my life so far. It's my turn to give something'."
Miss Riddell said she was "really nervous" about the cold.
"I'm taking in a massive duvet, so I can hide under it."
The annual event was organised by the high school to raise funds for World Vision's youth education and rehabilitation programmes in Bangladesh, Cambodia, India, East Timor and Rwanda.
Pupils raised $3200 in last year's 40 Hour Famine and $21,340 for World Vision over two terms last year.
This year's Youth Awareness Week runs from Monday to Sunday.
The 2009 theme is relationships, with a special emphasis on encouraging quality time between young people and their parents or care-givers.
Youth 2007, a survey of 10,000 secondary-school pupils, revealed that 45% felt they did not spend enough time with their parents.
X-It Youth Centre and Summit Youth Workers have joined forces with the high school to organise a week of activities.
