You should not leave a child unattended in a motor vehicle for any length of time. If children are trapped inside cars—especially in hot weather—they can suffer from heat exhaustion or heat stroke in a matter of minutes, leading to permanent disability or death. Heat stroke, also known as hyperthermia, can cause shock, seizures, irregular heartbeat, and heart attack, as well as brain, liver, and kidney damage. Leaving a child unattended in a car is also a form of neglectful supervision that is investigated by Child Protective Services.

In Oregon, leaving a child unattended in a motor vehicle is addressed under ORS 163.545, which makes it a Class A violation to leave a child under 10 years old unattended in a vehicle if the conditions present a risk to the child's health or safety. This includes situations where the child is exposed to extreme temperatures, which can lead to heat exhaustion or heat stroke. The law considers factors such as the age of the child, the length of time they are left unattended, and the vehicle's engine being on or off. If a child is found to be in danger, bystanders are encouraged to call 911, and they may be protected from liability if they take action to enter the vehicle to rescue the child under Oregon's Good Samaritan laws. Additionally, leaving a child unattended in a vehicle can be considered neglectful supervision and may be investigated by Child Protective Services, potentially leading to further legal consequences for the responsible adult.