Fields told KOKI her son used a ratchet strap from her car and then part of a clothes rack from inside a store to break the windshield of the car.
He then crawled inside and unlocked the car to get the toddler out.
"I'm just very proud of him," Fields said. "I'm glad that he knew what to do."
Police say the toddler was red-faced and in a bit of distress, but otherwise OK. He was checked out by paramedics at the scene and did not have to go to a hospital.
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Police say they found the mother of the toddler inside one store. She said she thought there was another adult in the vehicle when she got out. Officers questioned that, asking why she would shut the car off and lock it if that was the case.
Police say they still aren't exactly sure what happened.
Officers ended up giving the mother a $250 ticket under the Forget-Me-Not law. They say they did not arrest her for child neglect because the kid was OK and this was her first offense.
Police say the child remains with his mother, but there will be a Department of Human Services investigation.