A new government study finds that consumer products aimed at avoiding these tragedies aren't successful on their own.
The tragedies take place every summer. Children left behind in parked cars, or climbing in on their own.
According to the National Highway Traffic Safety Administration, heat stroke killed 33 children in cars last year. 49, the year before.
New research from the government agency and the Children's Hospital of Philadelphia found that new devices intended to help parents avoid such tragedies with child-detecting sensors and alerts are well-intentioned, but unreliable and inconsistent when used on their own.
Some were rendered ineffective by liquids or cell phone interference, others when children moved out-of-position and parents could be given a false sense of security.
While manufacturers work on improving technologies ... here are some safety tips:
-- never leave children unattended in a vehicle, even for a few minutes, even with the windows partially opened and even with the air conditioning on;
-- check the front and back of the vehicle before locking and walking away;
-- give yourself reminders. Place a bag, briefcase, or cell phone in the back seat if you need to.
-- and teach children that the car isn't a play area.
Keep keys out of reach of children so they can't enter an unattended car.
(Karin Caifa for CNN's Consumer Watch)