While going over the illness section of the handbook at my daughter's preschool orientation, the director told parents, "If we made every kid with a runny nose stay home, we'd have no children here." Kids get sick a lot and not every sniffle requires you to take a day off from work to nurse them back to health. But it can be tough to gauge whether your kid is too sick to go to school, and it often comes down to a judgment call.

Earlier this year, I took my 14-month-old son Ezra to the local urgent care clinic, where I got confirmation of an ear infection. It made sense, based on his fever, but as we drove home, I thought he seemed ... disoriented. I tried to shake it off -- I was still a new mum, probably overreacting.