The Food and Drug Administration says children under 2 years of age shouldn't use over-the-counter cold and cough medicines. The new warning updates one from last summer.

The FDA warned in August that children should not take these medicines unless a doctor says it's okay. Many companies voluntarily pulled infant medicines off the market. New evidence prompted the stricter FDA warning.

Two new surveys show most parents still think it's okay to use those over-the-county medicines. On Thursday, the FDA warned again that there could be dangerous side effects.

"Death, convulsions, heart abnormalities,” said Dr. Charles Ganley, director of FDA’s Office of Nonprescription Drugs.

They're rare but possible because it's so easy to accidentally overdose children under 2, even with a doctor's advice, because different versions of the medicines look alike but have different ingredients.

"It's simply not a case of sending someone out and saying 'buy such-and-such product and use it at this dose,' because it may not be the product that the health care provider is thinking about,” said Ganley.

The American Academy of Pediatrics agrees. Now the FDA is weighing whether to allow use up to age 11. Until that decision is made this spring, the FDA urges parents to:
-- Only use the measuring device in the box;
-- Follow dosing directions carefully; and
-- not to mix cold medications.

Many doctors say it's not a question of whether they safe but whether they work.

"You may have made the child temporarily more comfortable, but is it worth the risk of a seizure or death, even if that's very unlikely; is it worth that risk for a small amount of comfort?" asked Dr. Nathaniel Beers of the Children’s National Medical Center.

The industry backs the FDA's ruling.

"Safety has always been and continues to be our top priority," said the Consumer Healthcare Products Association in a written statement on Thursday.

So, to help a child's cold, use vitamin C or zinc, according to a new study. Even steam from a hot shower may help.

The bottom line, of course, is a cold simply has to run its course.