(KTVU) - Last month alone, eleven children in the United States died in overheated cars.
That's the highest monthly toll in nearly a decade.
Experts say a child's body can overhear three to five times faster than an adults, according to NoHeatStroke.org.
Since 1998 to today, 729 children died of heatstroke after being left in cars. That's an average of 37 children each year.
A review of media reports shows that 376 of those children- well over half- were "forgotten" by their caregivers.
Ten years ago, Beth Brown's husband accidentally left their child, who died, in a car.
Beth says, "I wish that I could teach people that this can happen to anyone. It has happened to all all walks of life, doctors, principals and teachers and rich people and poor people. It doesn't matter who you are, you are not immune to this happening".
When it comes to pets, many more die because they're more susceptible to heat stroke than humans.
Dr. Heather Kovac, a veterinarian, says, "Dogs can't sweat like people do. So they cannot cool themselves sufficiently as we can. So it feels very much how you are sweating and feel very thirsty and hot. Your dog is even more so".
Experts say you should never leave your pet or child in a car, even if the windows are partially rolled down.
At 75 degrees, the car can reach 94 degrees in 10 minutes and 109 degrees in 30.
At 80 degrees, the car can hit 99 degrees in 10 minutes and 114 degrees in 30.
At 90 degrees, the car can reach 104 degrees in 10 minutes and 119 degrees in 30.
At 95 degrees, the car can reach 114 degrees in 10 minutes and 129 degrees in 30.