As an emergency room doctor, I see a lot of kids – especially in the middle of the night. What makes parents worried enough to bundle up their little ones, sit patiently in hard waiting room chairs (sometimes for hours) and seek the advice of a physician? The top complaints I hear from toddlers and their parents in the ER are fever, fussiness and falls.

Judging the seriousness of an injury or illness can be very difficult, especially when a young child can't really communicate what he is feeling, when it started and what makes it better or worse.

Children can look terrible when they are sick or hurt. For example, when a child or infant has a fever, her entire personality is affected. Parents respond intuitively to the fussiness, decreased appetite and decreased energy levels of their children, which are some of the most obvious signs that a child is ill or injured. As a doctor, I rely on the parents' description of their child's behavior – so be specific about what symptoms made you worried.