This requires practice. The YELL stage. The worst case scenario. The child needs to find a new gear now and run. And while running, teach the child to yell for help.
Most children have shrill voices.
Rehearse this with your child. There IS a difference. When you have a moment, listen to a child scream on a playground. It sounds like banshee's wailing. Then listen as they call to a friend over a long distance.