"It might seem pretty extreme to some people, but after being in the army it's not really a big deal," he said.
McKinney is raising money for Leukaemia & Blood Cancer New Zealand and focusing heavily on raising awareness of depression and PTSD in first responders.
Last year, Whangarei firefighter Maaka McKinney completed a mammoth mission in order to raise money for Leukaemia & Blood Cancer New Zealand and awareness of post traumatic stress disorder in first responders.
He cycled the South Island and then ran from Wellington to Auckland - a total distance of 1800km.
McKinney has served New Zealand on battlefields in Bosnia - as well as working as a security contractor protecting troops and diplomats in war-torn Iraq.
Next Saturday on May 19,950 firefighters will climb the 1103 stairs of Auckland's Sky Tower in order to raise funds for Leukaemia & Blood Cancer New Zealand.
Among the 950 firefighters scaling the stairs, will be 64 Northlanders.
The participants, ranging in age from 16 to 76 years old, will gear up with full firefighting kit and breathing apparatus weighing up to 25kg.
To date this year, firefighters have raised over $750,000 towards a fundraising target of $1 million.
The funds raised will help Leukaemia & Blood Cancer New Zealand run their vital nationwide service supporting Kiwis and their families who are living with a blood cancer.
Leukaemia & Blood Cancer New Zealand General Manager Georgie Hackett said the support from brigades and their local communities is humbling.
"This fundraising is the backbone of our service and helps us grow our vital support for families living with blood cancer in their communities right across the country," Hackett said.
The Firefighter Sky Tower Stair Challenge has been running since 2005 and general manager of SKYCITY Hotels and Sky Tower said the event has raised nearly $6 million over the past 13 years.
The Stair Challenge
• 51 flights of stairs.
• 1103 individual steps.
• At 328 metres, the Sky Tower is the tallest building in the southern hemisphere.
• Firefighters will wear up to 25kg of kit.
• 950 firefighters will race up the Sky Tower in 2018.