Friends don’t let friends drive drunk. Friends don’t let friends vote Republican (or Democrat—or at all, depending on what the case may be). Where’s the bumper sticker that says friends don’t let friends ride bikes without helmets—or better yet, parents don’t let kids do the same?

A bicycle helmet is one of the easiest things you can buy to protect your child from injury. You buy a car seat, right? Do you pay for a flu vaccination—or even other pricier shots, such as RSV prevention drugs? You’ve also probably got smoke detectors, outlet covers and other protective devices in your home—so why not a helmet?

Knowing that many parents say that a bicycle helmet is simply too expensive, I have to disagree. If you ask your pediatrician, he or she can tell you where to get one cheaply. Many stores may have them for about $10. My daughter’s preschool held an event in conjunction with the nearest children’s hospital to make helmets available at $8 each. (They also had nurses there to help us fit the helmet and learn about its proper use.)

 I’ve heard of some events where people can even get them for as low as $5—or free if they qualify. And though parents on a budget may argue that it’s still the cost of an hour’s pay, I have to ask—is an hour’s pay worth protecting your child from a trip to the emergency room, possible injury or death?

Unfortunately, only 21 states have helmet laws in the United States. That’s too bad, considering that there are up to 85 million bicycle riders in the country, half of whom are over the age of six. 698 people died in bicycle accidents in 2007 alone, and the average victim was a sober person who was not wearing a helmet.

That may not sound like a lot to you, but about 540,000 bike riders end up in the emergency room every year due to injuries on their bikes; riders who don’t wear helmets are 14 times more likely to be harmed than those who wear helmets. Of those sent to the ER, 27,000 end up being hospitalized.

A helmet can prevent up to 88% of brain injuries, and if every bicyclist wore one, it could save the country healthcare costs of about $81 million.

There is really no excuse to not wear a helmet. Be a good example and wear one yourself, make your children wear them, and be safe.