The government is joining safety groups warning parents and other adults about the dangers of children being left inside hot automobiles this summer.
Deaths of infants and toddlers trapped inside hot vehicles have mounted in recent weeks. A researcher says 18 children have died of hyperthermia since the beginning of the year, eight of them reported since June 13.
That's the largest number of fatalities through the first half of a year since the researcher, Jan Null, began tracking the data in the late 1990s.
Many of the recent cases have involved children who climbed inside an unlocked vehicle on a hot day and then couldn't get out.
Each year, nearly 40 children die from heat exhaustion in vehicles.