Every parent's nightmare on Halloween? Tainted candy. And every year scores of hospitals offer to X-ray Halloween goodies to protect kids from the possible tampering of malicious strangers. But a far more common Halloween X-ray finding is likely to be broken bones.

In fact, there never has been a documented case of a child being poisoned by a stranger with Halloween treats. As for needles or razor blades in apples or candy, actual cases exist but are extremely rare, according to experts. The National Confectioners' Association has operated a toll-free hotline for more than 10 years. This line allows police to report incidents of alleged tainted candy. The group has no confirmed case of a child being seriously injured by tainted candy from a stranger.

The biggest threat to children's well-being during the prime trick-or-treating hours of 4 p.m. to 10 p.m. comes from something kids encounter every day — cars. On average, four children are struck and killed by cars every Halloween in the United States, according to a study by the Centers for Disease Control and Prevention (CDC). This is four times the fatality rate reported on any other night of the year. And because this number does not include accidents in driveways, parking lots, and on sidewalks, the actual number could be higher, according to the CDC.

Why is this night so much more hazardous? CDC experts say it's because most trick-or-treaters are out after dark, and that period of darkness is lengthened by the return to Standard Time, which happens just before Halloween. Also, children are dashing about in search of the best and most candy, often carelessly crossing streets in the middle of the block rather than at corners. Visibility's an issue, too. Kids' vision is often obstructed by masks and headdresses, so they may not have a clear view of the street. They might not see cars, and they could also trip and fall. And if children's costumes are dark, drivers may not see them.

Taking your children to a Halloween party is a great way to avoid both traffic and "stranger danger" issues. However, if your kids are going to make the neighborhood rounds, follow these suggestions to help them stay safe. At least one adult should accompany younger children. And that adult needs to stay focused on the supervisory role, resisting the temptation to stop and chitchat with adults along the way.

Kids old enough to trick or treat on their own will benefit from a pre-trick-or-treat huddle to discuss the risks. Also, talk to the parents of other youngsters to make sure you're all in agreement as to which streets or neighborhoods children are going to, and when they are coming back.

Costumes should be bright or have reflective tape attached. Also be on the alert for string, rope, belts and fabric that could choke a child. To avoid eye and face injuries, make sure swords, magic wands and other props are made from soft materials like cardboard, not from wood or metal.

Although instances of candy tampering are extremely rare, there are other very good reasons to dump out that bag of goodies and sort through the mound (other than snagging a few morsels for yourself). Be on the alert for items to which your child is allergic. And if you have children age 3 or younger in the house, pull out the round hard candies and peanuts that could easily lodge in their windpipe. Coated chocolates that don't contain peanuts are OK. To avoid hurt feelings, consider trading money or a safer candy for any suspect items you remove.

One final threat to children on Halloween is eating too much candy. Contrary to popular belief, numerous scientific studies have determined that candy and sugar do not cause behavior problems or hyperactivity in children. But pigging out on candy can certainly lead to upset stomach, vomiting and diarrhea. Plus, candy contains loads of fat, sugar and empty calories, which can make kids fat and cause cavities. It's probably best to limit consumption to a couple of pieces a day after dinner, which has the added benefit of being close to the time when most kids brush their teeth.