A 12-year-old Florida boy's quick thinking and love of "Stranger Things" helped him save a man from drowning. Now his mother wants other parents to learn from the near-death experience.

Christina Macmillan was out shopping on Labor Day when her husband called, telling her to pull over so he could tell her some troubling news involving their 12-year-old son Austen and his behavioral therapist, Jason Piquette.

Piquette had been drowning in the family pool in Wellington — near West Palm Beach — and Austen had saved him, Macmillan told USA TODAY on Wednesday.

"I was in shock," she said.

Underwater challenge gone wrong

Using a phone timer, Piquette and Austen had been competing to see who could hold their breath under water longer when something went terribly wrong, Macmillan said.

Footage from the family's security cameras shows Piquette floating motionless face-down in the pool. Austen checked the timer, saw it had been five minutes and knew that was too long.

Austen dove under water to check on Piquette. Finding him unresponsive, Austen then pulled him from the deep end and set him face-up on the pool's shallow steps.

Austen ran out of the front door yelling for help and went to two neighbors' houses but no one answered his cries. Austen quickly returned to the backyard and began administering CPR. He also tried to use Piquette's phone to call 911, but couldn't unlock it or access the emergency call button because of a cracked screen.

Soon after getting CPR, Piquette regained consciousness and began throwing up water and blood.

"I think I passed out in about 30 seconds and I don't know why," Piquette told Good Morning America. “I’m just so amazed at how strong he was and how wise he was in that moment. And I always want him to know that he is a hero."

A lesson from "Stranger Things"

Macmillan later asked Austen where he had learned CPR. He told her he remembered it from a scene in the show "Stranger Things."

The emotional, two-minute scene shows Joyce Byers (Winona Ryder) and Jim Hopper (David Harbour) giving chest compressions to Byers' unconscious young son Will (Noah Schnapp). Hopper beats frantically on Will's chest in desperation to revive him.

Mimicking those chest compressions, the home video shows Austen hitting Piquette's chest and bringing him back to life.

Austen's father arrived home a couple of minutes later, dropping his groceries on the way in out of shock at his son's panicked cries. His father called 911 and Piquette was admitted to the intensive-care unit overnight and kept on 100% oxygen, Macmillan said.

Even though Austen's quick thinking and determination helped save Piquette, he was shaken afterward, his mom said.

Macmillan said he kept asking if Piquette was going to be OK. After a "miraculous" recovery, he was released and able to give Austen a big hug the next day.

An important reminder

Part of the reason the incident shocked Macmillan is Piquette's health.

"I was really surprised that it was someone like Jason drowning in our pool because he's very physically fit and very good in the water," she said of the behavioral therapist, who has worked with Austen for nearly four years and is considered part of the family.

It's a reminder that drowning can happen to anyone, and that parents should teach their children CPR and how to make emergency calls, Macmillan said.

"The adults are supposed to be the protectors but what happens if something happens to an adult?" she said. "The child has to know what to do."

Macmillan knows that some people aren't so lucky. That's why she hosted a CPR training for close friends and family at her home this past weekend, when they learned how to perform it correctly from an instructor.

"I wanted to turn this into a more positive way to educate and bring awareness to CPR for other parents, so that this doesn't happen," she said.