Surveillance footage showed police responding to the report that the baby was left in National City car.
A mother in National City was arrested on Tuesday after leaving her baby strapped inside her car while she shopped, police said.
Police now say the mother has two children.
The baby was found by emergency personnel in an unconscious state, soaked in sweat from sitting in the direct sunlight, according to National City Police Sgt. Julian Villagomez.
Surveillance footage showed the woman left the car in the East Plaza Boulevard shopping center at about 3 p.m. for about 10 minutes while shopping at a clothing store nearby.
Police received a call from a maintenance worker, who noticed the 4-month old baby inside the four-door sedan.
When they responded, they broke into the car through the window to rescue the baby, who was unconscious. The baby was revived and taken to Rady Children's Hospital.
The baby is said to be okay.
The mother came out of the store -- Toda Moda, pictured right -- when she saw police near her car, and told authorities that she only left for a minute.
Witnesses described her reaction as non-chalant.
"She wasn’t sad or crying or anything," one witness said. "It didn’t even bother her. I don’t know how a parent can be like that."
Highs in National City on Tuesday reached about 75 degrees, but firefighters said the temperature inside the car could have gotten as high as 140 degrees.
Police identified the woman as Starley Cristal Geart. She was booked into jail on child endangerment charges.
The baby's case will be handled by Child Protective Services.