Question:
It is not only illegal but irresponsible to leave a small child unattended in a motor vehicle for a significant length of time. Hawaii law stipulates that a child under 9 years of age cannot be left in a motor vehicle alone for five minutes or longer. A car can quickly become lethally hot inside, even with the windows open. A small child or animal cannot survive long under such conditions. [WARNING! Do Not Leave Children Unattended, Chapter X: Safe Driving Techniques, Official Hawaii Driver's Manual]