Plunging into the icy-cold waters in mid-winter is enough to send shivers down anyone's spine – but knowing it's in memory of two very special boys could warm people up to the idea.

Mount Maunganui College students are daring the cold at Omanu Beach for their annual Polar Bear Plunge on Wednesday to raise funds for the Leukaemia Foundation in memory of Jed Roberts and Harrison Mundy.

Mount Maunganui College students Jamie Vulgar, Fletcher Swan, Perry Preston and Ruby Jensen survey the waters ahead of Wednesday's annual Polar Bear Plunge. Photo: Tracy Hardy.

Former student leader Jed passed away in 2011 following a 19-month battle with leukaemia, while 11-year-old Harrison Mundy lost his battle to cancer on February 16, 2014.

College sports director Terry Cochrane says the event originally began to raise funds for Jed, but when they received the sad news of Harrison's passing last year – they felt compelled to help him too.

'We approached Jed's family and asked if the event could also be about Harrison and they were all for it.”

Harrison's father Allan Mundy was also a teacher at the college.

Terry dares people to dress in orange – the leukaemia colour – and take the plunge into the freezing-cold waters with the students.

'There's rumours that a polar bear from Auckland Zoo is coming down and he's going to be the first to jump in,” he jokes. 'The polar bear reckons the water's really warm.”

The Mount Maunganui College annual Polar Bear Plunge is at Omanu Beach Surf Club this Wednesday from 8am.

People taking the plunge are encouraged to donate $3 towards the Leukaemia Foundation.

To donate to the Leukaemia Foundation click here.