The official start of summer comes later this month, but already children have died after being left unattended in hot cars, according to the nonprofit National Safety Council, drawing attention to an issue that kills an average of 37 children a year. The council released a report this month that says 742 US children died of heatstroke in vehicles between 1998 and 2017. Forty-two children died in these conditions in 2017, up from 39 the previous year. Just 21 states have laws regarding this issue, the report says; eight include the possibility of felony charges for individuals who deliberately leave...