Siblings Felicity and Hugo Brice are setting out to travel 97km each, the distance it takes for the rescue helicopter to fly from Mt Hutt to Christchurch Hospital and then back to base.
While some of the distance would be covered between home and school, they would start the month off by cycling to Pleasant Point and back.
Mother Alice Brice said they were hoping others would come along.
"We’re not expecting money, we’re just hoping for company on the ride."
Eight-year-old Felicity said she thought other children might want to join them as they might like "trying a new trail".
She and her little brother had completed the cycleway in the past, so she was looking forward to making new friends on the day.
Felicity, who is a year 4 pupil, was most excited about stopping to get an ice cream in Pleasant Point.
She had decided her ice cream on the day would contain "every flavour".
Her 6-year-old brother Hugo — a year 2 pupil — thought that sounded great.
He was excited to win a medal for raising $100 for the fundraiser, but he was trying to work out what he would get if he exceeded that amount.
After a discussion with mum, he said if they raised $150 they would get a medal and a pat on the back.
Mrs Brice said she and the children had been talking about when their family might need the rescue helicopter.
"We talked about getting sick and needing the helicopter to take us to Christchurch."
Felicity said that the adventurous family, who often went on overnight hikes, might need it "when we get hurt on a mountain".
The first person to contribute was a customer Mrs Brice had been talking to about her children’s fundraiser.
The customer had previously had an accident in Twizel.
When he paid for his purchase he passed her $50 and told her that was to go towards her children’s fundraiser.
Felicity was excited whenever she received money for the cause.
"It’s so kind."
Her mum said it had inspired her oldest child to do a "wee dance".
The family were looking to raise $500, but as they wanted a medal each Mrs Brice had created three accounts.
"Because I want one, too."
She felt it was a great cause and hoped others would sign up to raise money, as "you never know when you or your family might need a trip in the helicopter".
"The bonus for you is getting active in winter and teaching the kids about supporting others."
Mrs Brice said the ride would take four and a-half hours if lunch and an ice cream stop were accounted for.
"It is the last month of winter; it’s a good excuse to get out and get active."
She felt doing it with other children made it "way more doable".
They would leave Sir Basil Arthur Park at 10am on August 4.
