Thetoska Lehto, 23, of Glenns Ferry faces charges of felony injury to a child, DUI, and meth possession, Caldwell police said.
At about 4:40 p.m. Tuesday, officers responded to a report of an apparently unconscious woman in a car in a truck stop parking lot in the 3500 block of Franklin Road, police said.
Officers found Lehto passed out behind the wheel with the engine running. They also found a 14-month-old baby, red and sweating heavily, in the back seat of the car with the windows rolled up, police said. The temperature outside was about 95 degrees.
It took several minutes for officers to awaken Lehto and give aid to the baby, police said. The child was treated at a local hospital for heat exposure and later released to a relative, police said.
Lehto was evaluated by a drug recognition expert and arrested for driving under the influence of drugs, police said. She also was found in possession of methamphetamine and was booked into the Canyon County jail, police said.