Photo/Illutration In Sara Chikuma’s manga, her husband tells their daughter to honk the horn if she is locked inside a car. (From Sara Chikuma’s blog)

Twitter users flooded the social media platform with messages urging children to “hit the horn if you're locked inside a car” following the heatstroke death of a 5-year-old boy left inside a locked school bus in Fukuoka Prefecture.

The messages were retweeted rapidly, with many users posting positive comments, saying they had "told children right away."

One of those who tweeted the message was Dr. Rino, a Kyoto Prefecture pediatrician who posts about matters families should be careful about regarding young children.

"If you get locked in a vehicle, you should honk the horn," Rino thought, just as you would make a loud noise to attract rescuers if you were trapped in a collapsed building or buried in debris.

But many children are told not to get near the driver's seat. Rino points out the importance of teaching them to call for help repeatedly in the event of an emergency.

A manga advocating the same message has also attracted a wide response.

Sara Chikuma, 38, who drew the cartoon, said her husband told her about beeping the car horn if kids get stuck inside.

“That was an eye-opening idea,” she said.

Chikuma, who blogs on the experience of raising her children, then drew the manga. Both her daughter, 6, and 2-year-old son are in nursery school. 

Hitting the horn, however, should be the last resort for staying safe as for a small child just pushing the horn can be difficult to do.

Safe Kids Japan, a nonprofit organization that deals with the prevention of accidents involving children, lists several ways to ensure kids are not accidentally left behind in a car.

Parents or family members supervising children, it advises, should always put their wallets or bags in the back seat where children usually sit.

That way, if adults get out of the car in a rush or even for a short period, they are more likely to check the back seat, lessening the chance of a child being left behind.

The NPO also calls on people to err on the side of caution and take action if they see any children left alone inside a vehicle.

Though it is hard to tell from outside a vehicle if the air conditioner is on, the NPO advises that people should consider it "a matter of emergency" and call an ambulance or the police.

(This article was written by Satsuki Tanahashi and Yusuke Ogawa.)