After a month in a coma, Cairney also lost his memory from a year before and after the crash.
His talk will discuss the road to recovery from his injuries, as well as the decisions that led him to get into the car on that tragic day.
Cairney, who lives in Wanaka, will be supported during the talk by his mentor and friend Graham Clarke, who has his own story to tell.
His son was killed after getting behind the wheel after he'd been drinking.
Boys' High principal Nic Hill has invited students from all schools around the city and the wider community to hear the story of "sadness, recovery, love and strength".
Hill said the school is encouraging students to have emotional conversations about alcohol and driving.
"These are conversations that we as adults have to be starting. There is a parental role in making sure our boys are equipped to be safe," he said.
- Star.kiwi