Guest blogger Daniel P. McGee, MD, is a Spectrum Health Medical Group Physician who practices as a pediatric hospitalist at Helen DeVos Children's Hospital.

I was recently a guest WOOD TV-8 to discuss arsenic found in organic baby formula. It's important to recognize that just because something is called "natural" or "organic," like this baby formula was, doesn't automatically mean it is safe or healthy.

Thinking about this brought to mind a related idea—what are the common "old wives' tales" many parents take at face value? Here are a few to consider:

If your son goes outside with wet hair, he can get a cold.
False. Colds are caused by viruses, period. That said, it's good for a child to have dry hair and a hat on when they go outside in the winter, since so much body heat can escape through the head. If you are trying to prevent colds, the best thing you can do is help your child develop good hand washing habits.

If your daughter sucks her thumb, it will ruin her teeth.
False. Thumb sucking helps calm babies and young children and can be considered good for them. However, if children continue this habit as they get older and their permanent teeth are coming in, it can affect their teeth.

If your son cracks his knuckles, he will grow up to have arthritis.
False. However, cracking can lead to problems over time, as it may weaken the ligaments in your child's fingers and could make them more prone to injury. If your child likes to crack his or her knuckles, help them break the habit.

Children can only get tetanus if their skin is punctured by something rusty.
False. Tetanus exists on many surfaces, including those that appear clean. The tetanus bacteria can also live in an animal's mouth, so, for example, if a boy gets a dog bite, he could get tetanus. Children with burn injuries are at high risk for tetanus as well.

Reading in the dark will damage your child's eyesight.
False. Reading in the dark won't hurt children, but their eyes may get tired sooner. Support their reading habits by making sure there is good lighting wherever they like to read.

Have you heard any other old wives' tales that I can address?

- Dr. McGee