WASHINGTON, Washington State - Leaving children in parked cars in the blazing heat of summer: it's so obviously wrong, yet it happens in the US with astonishing regularity and with tragic results.From 1998 through 2013 in the US, officials say, an average of 38 children a year have died of heat stroke in a car - most of them younger than five years. So far in 2014 the toll is 17, prompting a national campaign urging parents and care-givers never to leave a child alone in a parked car.US transport secretary Anthony Foxx, a father of two, said at the July 24 2014 launch of a 'Where's Baby? Look Before You Lock" drive: "Every summer it seems that we live out the same nightmare."MORE VULNERABLETo make the point, thermometers fitted to a dark green Chevrolet Cruze sedan at the launch in Washington showed the air temperature at 26 Celsius (but 36 in the car) - and that on an overcast day.Have you forgotten a child in your car? It's so easy to do when your hassled or harried! Tell us about it - anonymously if you wish - and what you're doing to avoid a recurrence. Email us and we'll publish your thoughts or use the Readers' Comments section below...About 30% of children killed by heat stroke in a car got into the vehicle by themselves but 52% were left by a forgetful adult, the National Highway Traffic Safety Administration has reported.Pediatrician Leticia Manning Ryan of the Johns Hopkins Children's Centre in Baltimore, Maryland, explained that young children were particularly vulnerable because their body temperature could rise three to five times faster than that of an adult."When a child's internal temperature gets to 40C major organs start to shut down," she warned. "When the child's temperature reaches 42C the child can die."Foxx reported that, more often than not, children were left in cars because stressed parents and care-givers had memory lapses. "Based on the data we have, often it's being fatigued and overwhelmed that leads to these kinds of tragedies."Tragic tales of children - many of them buckled into special child seats that are mandatory on US roads - are a regular item in US news coverage. In the most sensational case so far in 2014 a Georgia man left his 22-month-old son inside an SUV that he parked outside the Home Depot store where he worked. At his ongoing murder trial, police alleged that Justin Ross Harris, 33, was more interested in "sexting" a teenage girl than caring for the welfare of his baby, Cooper.In a online survey, 115 of American parents - two-thirds of them men - admitted leaving a child locked in a parked car by mistake. That represents more than 1.5-million parents, said Public Opinion Strategies, which conducted the study at the start of 2014.'SMASH A WINDOW'At Thursday's campaign launch Reginald McKinnon painfully recalled the day he took his 17-month-old to a doctor's appointment then rushed to his telecoms job in Florida - forgetting to drop her off at the nursery."To my horror, I realised (on returning to the vehicle at the end of the working day) that Peyton was still in her car seat," he said. "I heard someone screaming - it was me."Two years earlier the NHTSA studied three devices which claimed to detect the presence of a child in a locked car but concluded that their performance fell short of satisfactory.More than 5800 people have signed an online petition launched by KidsAndCars.org, an advocacy group, urging US president Barack Obama to fund more research into such devices."It's sad but the technology is not there yet," NHTSA acting administrator David Friedman said. "Until it is, adults are advised to put something they'd instinctively reach for at the end of a car journey - a cellphone, a laptop, a handbag - right next to their child."And never to let youngsters play in a parked vehicle."Should a person happen upon a child alone in a locked car, Foxx said, they should immediately call the police or firefighters. Or smash a door window.