What procedure would be taken in a hospital ER if a child was found unconscious in a public place?

CPR. You need to perform CPR after calling for help. Chest compression is 15:2 breaths when there two people. When one person, you do 30 compression to 2 breath.
Examination. Fully examining the child to determine if any trauma may have cause the unconsciousness. Xrays and lab testing will most likely be done. Quick and early assessment of any unconscious child is essential for saving their life. The closest emergency department is the place to get started.