Judging other kids level of sickness.
Then judging the child's mother.
I see you shaking your head.
You might like to ponder this from the New York Times.
The Cough-and-Sniffle Question: When to Keep a Child Home?
By PERRI KLASS, M.D.
Published: February 10, 2009
Keep your child home from school if there’s fever, or if the child feels too crummy to participate -- but don’t worry so much about the runny nose in the row behind.