MOBILE, Ala. (WKRG) – So far, 15 children have died in hot cars this year, and one of those was in Monroeville, Alabama.

Jennifer Bowden left her 7-month-old son Zachary in a hot car for nearly three hours.

When he arrived at the emergency room, his core body temperature was 110 degrees- he died from hyperthermia.

And just last a week a 3-year-old Houston boy was found in cardiac arrest after only 30 minutes in a hot car.

So what actually happens when the body reaches hyperthermic levels?

“You can experience dizziness, nausea or vomiting your heart rate can increase–some patients even have changes in mental status- a common symptom is sweating,” said Mandy Allenbach, a nurse practitioner.

And it can take just 10 minutes for those symptoms to start. In just half an hour, children can die.

WKRG’s Alison Spann and News 5 intern Savannah Kelsey tried sitting in a news car with the windows rolled up for several minutes, and in just a short time, the temperature climbed by more than 30 degrees.

Louisiana is one of 20 states that have laws that specifically address leaving in a child in a car.

54 percent of children who died hot cars from 1998-2015 were forgotten by their caregiver– mostly parents who were driving to work and forgot their child was in the backseat.

Mark McDaniel, PhD, told WebMD that it can happen to any parent, especially when there’s a deviation in routine.

“If the child has fallen asleep in their car seat, which is usually behind the driver’s seat, there is no visual information to remind you that there is a kid to drop off and if you have not done it day in and day out, you need a cue,” McDaniel says. It’s also akin to how you know you drove to work, but don’t remember the drive.

One of those tips to give parents an extra clue is to leave a phone or a purse in the back seat, a means of being extra safe rather than tragically sorry.