An eight-year-old boy is being hailed as a hero after skills he learned from watching John Cena on a Nickelodeon TV show helped save his younger sister's life. Jaxson Dempsey was on his way to a haircut late last month when his 20-month-old sister Leila began choking on a chicken nugget from McDonald's. "It made me feel scared because I thought she was going to die," said Jaxson. "But then this thing came into my mind. I told my dad to pull over and I started to pat her back." This "thing" the second-grader had remembered was an episode of the Nickelodeon hidden camera prank show The Substitute, in which celebrities go undercover in classrooms as substitute teachers. What Jaxson had in mind was a season one episode featuring John Cena, where Cena teaches a class of young students the basics of CPR on a dummy named Chuck. With the episode in mind, Jaxson acted quickly, leaning his sister forward and using the heel of his hand to slap her back between the shoulder blades, ultimately dislodging the stuck chicken nugget in about 30 seconds.