At the Dunedin physiotherapy pool on Saturday, five teams of up to six people dressed up and bathed in a paddling pool filled with icy water for the 360 Heart Stopper Challenge Heart Kids fundraiser.
Candice Makene’s team donned tropical island garb to distract themselves from the bitter temperature.
"It’s a sort of psychological trick to make us think we feel hot."
Ms Makene’s 6-year-old son Chaedon was a "heart kid" and she wanted to give back to the charity which helped the families of children like hers.
"They are there for people who can’t afford the little things, so that’s what this is all about."
Heart Kids Otago service co-ordinator Cecilia Sullivan-Grant said the participants were "really brave".
"Because it’s something I wouldn’t do. It gets really cold in there.
"The idea comes from when they’re doing surgery on the little ones; they pack their hearts in ice."
The fundraiser had run nationally for 10 years, but it was only the second or third time it had been held in Dunedin, she said.
Organisers would not know until the end of the week how much money was raised.
They hoped to make the event bigger next year, Mrs Sullivan-Grant said.
"We’re very thankful to the physio pool for letting us hold the event here, because it’s a great facility."
