St Chads' Trust's centre manager James Leigh encouraged locals to take part. The money would go towards helping people with intellectual disabilities.
St Chads' Trust runs programmes for people with any kind of disability, helping them develop life skills and helping facilitate their inclusion into the wider community.
"This is an excellent way for people to help our cause and to raise our profile," he said.
"So everyone, bring along your friends and family and support this fantastic event and in turn, St Chads Trust and the Waiariki Women's Refuge.
A Waiariki Women's Refuge spokeswoman said money raised would help the women, children and families the refuge supported. It would allow the refuge to supply necessities and items, such as underwear, toiletries, nappies, colouring books and crayons for children.
Each pool plunge or fire walk costs $5, cash only. Event-goers can walk or plunge as many times as they want. Minimum age to enter is 14 and anyone taking part aged between 14 and 17 must have parental or legal guardian's consent.
Plunge divers should take swimwear, while changing facilities will be provided. Fire walkers must be barefoot. Health and safety provisions will be in place for the McDonald's Rotorua-supported event.
For more information, visit facebook.com/fireandicerotorua