Locals came out dressed as superheroes, ladybugs, soldiers and pirates to take the icy plunge on Saturday.
The annual Heart Stopper Challenge, run by Heart Kids Rotorua, was held at the Rotorua Aquatic Centre for people to raise money and show support for children who suffer from heart disease.
Seven teams, each with about four to six members, jumped into a pool of 10C water for six minutes.
This was to mimic what it feels like for a child to have icy water flushed through their chest during heart surgery.
Heart Kids Rotorua chairwoman Allyn Boyd said there was a successful turnout at the event.
"All the participants turned up and there were lots of spectators so it went really well."
Ms Boyd and her family support worker, who weren't intending to take the plunge, raised an extra $200 to join in and put their heads under the water.
"It was absolutely freezing and the wind didn't make it any warmer either," Ms Boyd said.
Rotorua's Labour candidate, Ben Sandford, made it to the challenge, where he and his team took the plunge as well.
Local Jacinda Higgins, whose daughter has gone through heart surgery, said it was a special moment.
"Me and my younger brother dressed up as soldiers as our team name was 'Emma's Army'.
"I got a bit emotional once I hopped in the freezing water because it's hard to imagine that Emma has had to go through this," she said.
This is the first year Ms Higgins has participated in the Heart Stopper Challenge and she plans to take part every year.
"It felt really good to show support and give back to Heart Kids and show appreciation for everything they do."
Heart Kids Rotorua has raised more than $3000 in online donations from the challenge so far, which will be open until the end of the month.
For information on how to donate, go to heartstopper.org.nz/event/hscrotorua17.