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The Hot Car Calculator Tool Can Help Prevent Heatstroke Illness and Death

Updated: Feb 23, 2021

A new tool was recently developed to help caregivers understand the severity of leaving children alone in hot cars. Dominik Czernia, a Ph.D. student at the Institute of Nuclear Physics in Cracow, and Lukasz Bialek, MD, created The Hot Car Calculator as part of their Omni Calculator Project. Czernia says, “My goal is to help parents understand how risky it is to leave their child unattended in a hot car even for a few minutes.” Czernia and Bialek find it very important to make parents aware that their vehicles can “become a death trap in the blink of an eye.”

Heatstroke causes an average of 38 deaths per year. 2018 was the deadliest year yet, with 53 children dying from heatstroke. Czernia says, “At 70°, even on a cloudy day in a light-colored car, it only takes 45 minutes for a child’s body temperature to reach 100.4°, causing hyperthermia, sweating, and thirst. In a darkly colored car, things move even faster.”

What Does the Hot Car Calculator Do?

The Hot Car Calculator serves as an educational warning tool for parents and caregivers. It shows the dangers of leaving children alone in hot cars by updating a car’s rising temperature minute-by-minute.

A graph with two interactive curves represents the calculator's results. The blue curve shows how quickly the air temperature inside of a car changes. The yellow/red curve shows the body temperature of a two-year-old boy over time. The graph also highlights when a car’s internal temperature becomes dangerous and life-threatening to children.

Fill out each category of the calculator, including:

  • Outside temperature

  • Calculations based on (cloud cover, solar radiation)

  • Cloud sky coverage (0%-100%)

  • Car color (light, dark)

  • Windows (Closed, partly open)

You can change the settings each time you fill out the calculator to see the difference between a sunny/cloudy day, and a light/dark colored vehicle. No matter your results, you should never leave a child alone in a car, not even for a minute.

I filled out the hot car calculator using typical temperatures and cloud ratios during the summer. My results were staggering. For an 80° day with scattered clouds in a dark-colored car, the air temperature in my car could reach as much as 147°.

Within 40 minutes, a child’s body temperature will reach 102.2°, which leads to severe sweating, flushed, increased heart rate, and children with epilepsy may begin convulsing. At 110 minutes, a child’s body temperature reaches 105.8°, and children experience severe headache, dizziness, confusion, hallucinations, delirium, and it becomes a medical emergency.

Why Does My Car Get So Hot?

Czernia says, “It is because of the greenhouse effect occurring inside the vehicle. Car windows are transparent to light radiation and they prevent thermal radiation from leaving a locked car.” He says that solar radiation then makes its way through a car and heats the interior dashboard, seats, and the floor. These heated elements then emit thermal radiation, but the closed windows do not allow this radiation to escape the vehicle. Czernia says, “This trapped heat radiation causes the cabin temperature to increase dramatically. Cars turn into hot ovens.”

What to Do If You See a Child in a Hot Car

You should always call 9-1-1 immediately and then assess whether the child is conscious or not. Many states have good Samaritan laws, which allow bystanders to break open car windows to rescue trapped children and animals. Animals are just as at-risk for heatstroke-related illness and death as children. Never leave a child or pet alone in a car.

Dziękuję bardzo (thank you very much) to our friends in Poland for their work on this important issue!

The Institute for Childhood Preparedness has partnered with to prevent heatstroke deaths. We work hard to educate the public and keep childcare centers safe and secure. Find out if your childcare facility has a check-in policy, where the facility will call you if your child does not show up to childcare that day. It could be the difference between life and death. To have us perform a site assessment or to schedule an emergency preparedness, response, and recovery training, contact us today.


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