Cop saves three-year-old from hot car she was locked in overnight

This is the heart-stopping moment a Florida cop saves a toddler's life after she was left in a hot car overnight.

Quick-thinking Seminole County Deputy Bill Dunn ran with the three-year-old girl in his arms, his hands carefully behind her head, as he rushed to drop her in his vehicle and blasted the air conditioner.

He thought she was dead until he saw the youngster's eyes flutter after she felt the cold blast on June 17, Fathers Day.

The child was left in the vehicle overnight after she and her mother 33-year-old Casey Dylan Keller took a trip to the liquor store the day prior, but Keller forgot to take her child out of the car afterwards. She has been charged with child neglect, reports The Daily Mail.

In the cop's rescue video he puts on his car sirens and drives the girl to the hospital.

In his bodycam footage he's overheard urging the girl to pull through saying: "It's OK, baby. Talk to me! You're OK".

"Sadly, I didn't think she was alive when I got to her. I felt for a pulse, I didn't feel a pulse," he said to Fox 13.

"Once the cold air hit her, that's when I started noticing her eyes kind of fluttering," he added.

In the video when he arrives to the hospital, he carries the little girl onto stretcher. Dunn, who is also a father, waited for three hours at the emergency room until he was assured the child would be okay.

The bodycam footage ends with Dunn walking back to his car and slumping over, exhausted with the adrenaline-rush rescue.

"It was a heck of a thing to experience that adrenaline dump. And then when it finally goes away, how it really does affect the body," he said.

Deputy Bill Dunn saved a three-year-old girl left in a hot car overnight on June 17. Photo / Fox News 13

"Sometimes we're able to have a moment like this that makes it all worthwhile," he added.

Three days later he got to reunite with the healthy three-year-old.

Dunn rescued her from the sweltering vehicle after the child's mother Keller called police on the morning of June 17, claiming her car had been stolen and her child was inside.

Cops later learned that the girl's mother had actually gone on a liquor run and forgotten to take the young girl out of her car seat - leaving her in the hot vehicle overnight.

The car was found in the apartment complex parking lot, turned off and with all the windows rolled up, NBC reported.

Dunn saw the girl going in and out of consciousness, and said her eyelashes were fluttering.

"He pulled her out, put her under air conditioning in his cruiser, and rushed her to the hospital," a tweet from the Seminole County Sheriff's Office's read.

Keller was arrested and charged with child neglect with great bodily harm and is held in the John E Polk Correctional Facility on $15,000 bail.

Mom Casey Dylan Keller was charged with child neglect causing great harm. Photo / news.com.au

Days after her rescue, the girl's father called the Sheriff's office, asking to speak to Dunn so he could say thank you.

During their conversation, Dunn asked if he could meet the little girl, to which the father said yes.

"It was good for me, it was healthy for me to be able to see her healthy and up running and acting like a three-year-old should act," the hero cop said.