Why do ‘hot-car deaths’ happen?

A child’s body heats up three to five times more quickly than that of an adult

A child’s body heats up three to five times faster than an adult’s body as they have not yet fully developed the ability to cool down. Stock photograph: Getty Images

Hot-car deaths are more common in infants because a child’s body heats up three to five times faster than an adult’s body as they have not yet fully developed the ability to cool down.

So called "hot-car deaths" - when babies and toddlers die after they are accidentally left strapped in their safety seats - are becoming increasingly common in North America where parents leave a child for too long in a car.

An average of 38 children in the United States die from heat stroke in a car each year with numbers increasing ten-fold between 2003 and 2013.

The increase appears to be connected with vehicle safety precautions introduced in the early 1990s which mean children no longer sit in the front seat of cars but were strapped into safety seats in the back.


While these measures mean no child has died due to an airbag in the US since 2003, the number of children dying due to heatstroke is on the rise.

Even on seemingly mild days, when temperatures only reach the late teens or early 20s, children left in vehicles are at risk of heatstroke.

Professor David Diamond, a neuroscientist from the University of South Florida, says in just half an hour a car’s interior can get 35 degrees hotter and, depending on the clothes the child is wearing and when the child last drank something, an infant can die of hyperthermia in just 15 minutes when it’s 23 degrees outside.

He added cool weather or opening a window a crack was no guarantee of safety and overdressed infants were also at risk even when temperatures were as low as 10-15 degrees.

Prof Diamond told the parents.com website parental negligence rarely plays a role in these deaths and underlined the ability of the part of the brain which controls our everyday habits to delete memories of last minute changes to schedules.

For example, if a parent is used to dropping their child off at the childminder at a certain time every day, the brain might struggle to process an earlier drop off time.

“If you’re tired or distracted by worries, or - worse - if you’re not the person who usually takes the kid to the sitter’s, your habit system can erase that plan with appalling ease,” said Prof Diamond.

“You go straight to work on auto-pilot, spacing out on the fact that your child is with you in the backseat. You even develop false memories of dropping him off.”

Parents whose children die in these circumstances also often face legal repercussions in the US, where nearly half the parents of a child who died after being left in the car faced charges.

In 81 per cent of these cases there was a conviction.

So what can be done to ensure your family never has to go through the tragedy of a hot-car death?

- Always put your mobile phone, purse, bag or anything else you’ll need that day on the floor of the backseat so that when you pick them up, you’ll see your child.

- Sit younger (or quieter) children behind the front passenger seat where they are more likely to catch your eye.

- Keep your child’s teddy bear in the front passenger seat as a reminder that you have a baby on board.

- Ask the baby-sitter or childcare facilitator to always call within in a few minutes if your child is late turning up.

Sorcha Pollak

Sorcha Pollak

Sorcha Pollak is an Irish Times reporter and cohost of the In the News podcast