American researchers revealed how different types of cars warmed up on hot days when exposed to shade and sunlight and how these differences would affect the body temperature of a hypothetical two-year-old child left in a vehicle.
A study published on Thursday in the journal Temperature reported that a young child trapped in a car under the sun for one hour may suffer heat injury or even die from hyperthermia.
Scientists cannot predict exactly the temperature when a child will suffer a heatstroke, but most lethal cases involve a child's core body temperature rising above 40 Celsius degrees for an extended period.
In this study, the researchers from Arizona State University and the University of California at San Diego used data to model a hypothetical two-year-old boy's body temperature.
The team found that a child trapped in a car in the study's conditions could reach that temperature in about an hour if a car is parked in the sun, and just under two hours if the car is parked in the shade.
Researchers used six vehicles for the study with two identical silver mid-size sedans, two identical silver economy cars, and two identical silver minivans.
During three hot summer days with temperatures above 37 Celsius degrees in Arizona, researchers moved the cars from sunlight to shade for different periods of time throughout the day, and measured interior air temperature and surface temperatures.
For vehicles parked in the sun during the simulated shopping trip, the average cabin temperature hit 46.7 Celsius degrees in one hour. Dash boards averaged 69.4 Celsius degrees, steering wheels 52.8 Celsius degrees, and seats 50.6 Celsius degrees in one hour.
For vehicles parked in the shade, interior temperatures were closer to 37.8 Celsius degrees after one hour. Dash boards averaged 47.8 Celsius degrees, steering wheels 41.7 Celsius degrees and seats 40.6 Celsius degrees after one hour.
The different types of vehicles tested also warmed up at different rates, with the economy car warming faster than the mid-size sedan and minivan.
Hyperthermia and heatstroke effects happen along a continuum, the researchers said. Internal injuries can begin at temperatures below 40 Celsius degrees, and some heatstroke survivors live with brain and organ damage, reports Xinhua.
