Norovirus, often called the stomach flu, is back, closing down a college in Michigan and sickening kids and parents nationwide. It sure was topic No. 1 at my daughter's school bus stop this morning.

One mom recounted her family's harrowing weekend spent dealing with projectile vomiting, diarrhea, and headaches. Another gave a worried look at her third grader, who had woken up with a tummy ache. She decided to take him back home rather than letting him board the bus.

Wise move, mom.

This has to be one of the saddest statistics ever printed in a medical journal: The number of American children taking medication for type 2 diabetes more than doubled from 2002 to 2005, particularly among teenagers. That may be partly because more children are being screened for diabetes or because drugs are more often being used to treat metabolic syndrome. But the recent rise in childhood obesity is the obvious first suspect because overweight and obese children are more than twice as likely as their normal-weight peers to develop the disease.

Diabetes is a horrible disease, and no child should have to start dealing with it as a teenager. It's time for us parents to think about how to diabetes-proof our children. Here are five ways to start:

Cognitive behavioral therapy can help children struggling with mental illnesses such as anxiety disorders, obsessive-compulsive disorders, and depression. But finding good CBT can be really tough, particularly since some child psychologists say they do CBT but don't really. It's a precise art.

Unlike talk therapy, cognitive behavioral therapy focuses on teaching the patient practical skills. A depressed person might get out of the house and do something enjoyable or learn to replace "I'm no good" thoughts typical of depression with "I'm pretty good at this." An anxious patient, for example, learns step by step to manage tasks that the illness has made difficult or impossible and practices those skills until they become comfortable. "One of the main vehicles in cognitive behavioral therapy for treatment of anxiety is teaching the patient how to confront what they're afraid of," says Anne Marie Albano, coeditor of a study in the online New England Journal of Medicine that showed that CBT is as good as antidepressants for treating anxiety in children and that CBT and antidepressants combined are even better. "We call this exposure."

Richard Kanowitz told me a story that is every parent's nightmare: He and his wife put their 4-year-old daughter, Amanda, to bed sick one night, and "in the morning, she was gone." Amanda had died of influenza B, the plain old seasonal flu.

The Kanowitzes had called their pediatrician that evening because Amanda was pale and sluggish. The doctor told them that if they kept Amanda hydrated she'd be OK. In almost every case, that would have been true. But children do die of the flu; 83 children died last year, and 92 percent of them had not been vaccinated. Most of them had been healthy, like Amanda.

If it seems as if way more kids have food allergies now, you're on target. The number of children diagnosed with food allergies has gone up 18 percent in the past 10 years, according to new numbers from the National Center for Health Statistics. Four percent of kids now have food allergies, or about 3 million children.

This means a lot more than just the hassle of bringing nut-free snacks to school. Food allergies land children in the hospital about 9,500 times a year. Perhaps as many as 150 people die each year from food-induced anaphylaxis, most of them teenagers and young adults. The only way to avoid an allergic reaction is to avoid the food, which can be difficult. "What you're seeing is an increase in children with food allergy and no improvement in treatment or diagnostic options," says Anne Muñoz-Furlong, chief executive officer of the Food Allergy and Anaphylaxis Network.

The earlier a teenager starts drinking and using drugs, the more likely he or she will struggle in adulthood with substance abuse, job performance, and personal relationships. But is that because troubled children are more likely to use, or because the mind-altering substances are to blame? Society all too often sends a mixed message, on one hand saying that all substance use is harmful for teens, while on the other saying that it's normal for teens to try drugs and alcohol, and most turn out OK. That makes it easy for parents to think, hey, I've got a good kid here, he'll be OK. Well, maybe not.

Knowledge is power in parentland, and here's the first solid evidence that the "no drinking or drugs" parents are right. A new study published in the October Psychological Science found that even "good kids" are more likely to end up in trouble if they start using drugs or alcohol early in life. By looking at a group of nearly 1,000 people in New Zealand who have been studied from age 3 to age 32, a group of researchers in the United States, New Zealand, and England were able to see that those who started drinking or using marijuana regularly before age 15 were far more likely to fail in school, be convicted of a crime, have trouble with drugs or alcohol, or get pregnant in their teens.

The federal government's new standards aimed at reducing the amount of lead in air are good news for children, for whom air pollution has been one of the big remaining sources of exposure to this toxic metal. Twelve states will violate the new standard, which cuts the amount of lead allowed in air by 90 percent. Alabama, Colorado, Florida, Illinois, Indiana, Minnesota, Missouri, New Jersey, Ohio, Pennsylvania, Tennessee, and Texas are the dirty dozen; they have factories, such as lead smelters or battery recycling operations, that emit lead. Children can be exposed to airborne lead by breathing particles or by touching dirt outside or surfaces inside where lead particles land, then putting their hands in their mouths.

The Environmental Protection Agency got moving because of a court order that came out of a lawsuit on behalf of people who lived near a lead smelter in Herculaneum, Mo., where children had elevated amounts of lead in their blood. "This is a big step forward for children's health," says Gina Solomon, a physician and senior scientist for the Natural Resources Defense Council, which lobbied for tighter lead controls. But, she adds, the reductions won't be fully in force until 2017, "too late for an entire generation of children." (Here's the NRDC's map showing lead-tainted sites throughout the country.)