The toddler’s father, 28-year-old Abraham Martin, is in jail, charged with aggravated child neglect.
Action News Jax spoke with several neighbors near Martin's parents home, where he was arrested Monday, and at the Madison Commons apartment complex where the child was found.
"What I heard from [the 2-year-old's] grandma was he took the keys and then he went into the car, and I guess he was locked in there and couldn't get out," said neighbor Jaslynn Morel.
But a portion of the Clay County Sheriff's Office report could contradict that. It says the apartment "has a single entry/exit door with a chain latch over five feet in height from the floor."
Action News Jax asked Morel what the child looked like what he was taken to the hospital.
"He wasn't breathing," Morel said.
The Department of Children and Families said it’s also investigating, and that Martin's three other boys are safe with family.
Deputies believe the temperature inside that vehicle was upwards of 105 degrees.