Cysts grew in Cameron's lungs before he was born, his mother Caroline Witsman said. The disease is called congenital cystic adenomatoid malformation, Witsman told ABC affiliate WFTV, and when Cameron was four months old, he underwent a double lung transplant.
"If he would not have had the transplant he would not be alive today," Witsman said. "There were quite a few instances where we didn't know, but thank goodness he pulled though all of those."
Cameron, who has already survived so much, recognizes the importance of serving others; he said what he likes about firefighters is "helping people."
So Cameron's new employer, the Eustis Fire Department, put him to the test.
"His dream has always been to be a firefighter," said Chief Rex Winn of the Eustis Fire Department. "And we tried to make that dream come true."
The 6-year-old was given his own uniform and went to work, shooting down cones with a fire hose and even dragging dummies down the street, all with a huge grin across his face.
"Pretend fires, he runs all these pretend calls at home, so to get this opportunity for him has just been such a blessing, and I'm so thankful," his mother said.
"It's just so amazing to see that kind of fire in a young man," Winn added. "That young man's excitement and a dream that we can make happen for him. That's the good part of our job."
"Cameron wakes up with energy and he never wants to go to sleep at night," his mother said. "He's full of energy, vibrant smart, kindhearted, loves helping people."
While Cameron's energy is up, he still has a suppressed immune system, according to WFTV, requiring him to be home-schooled and take several medications a day.
"There was a few times where I was called... 'Cameron's doing really bad, I don't think he's going to make it, you need to get here now,'" Witsman said. "I can't even put into words how amazing it is that we're here today and we're doing well."
And the celebrations didn't stop at the fire house. Cameron was the guest of honor at a local parade today, during which he rode on a firetruck and handed out candy.
"It's such a heartwarming feeling. So awesome that they've taken this opportunity to really make his day and make his years," Witsman said.
And how did Cameron feel about the new job? "I'm proud to be a firefighter," the 6-year-old said.
ABC News' Tom Llamas and Susan Aasen contributed to this report.