When you made that first drive home from the hospital with your newborn, you probably had the car seat professionally installed. You probably triple-checked each strap and swerved around every crack in the road, quaking with love and paranoia.

It would never occur to you that four years later, you might be the kind of harried parent who would throw your grocery bags in the backseat, turn on the ignition, and hear your toddler squeal, “Mommy! You forgot to buckle me in!” as you prepare to pull away.

Alas, it’s surprisingly easy for even conscientious parents to forget to buckle or unbuckle their kid in their car seat. This can have terrible consequences. Gene Weingarten’s devastating, Pulitzer-Prize-winning story on the children who die when their parents leave them in hot cars showed that parents of all income and education levels have done it. If you’re stressed, tired, or coping with changes in the routine, it could happen to you.

As parents, we've heard so many tips and tricks to make sure this never happens. Download an app. Put your kid’s toy in the front seat. Put your shoe in the backseat. Give the kid your smartphone (actually, don’t do that, my kid threw up all over it).

Evenflo’s new SensorSafe car seat might be the easiest way to remember, period. Every time you buckle the child’s chest strap, an embedded sensor transmits information via radio frequency and Bluetooth to a wireless receiver and your phone. The sensor sends notifications to you if, for example, if your child has unbuckled himself while the car is moving, or if you’ve been driving for longer than two hours.

Most importantly, every time you turn off the car, the receiver plays a loud, shrill jingle to remind you to get your kid. You can’t ignore that sound, any more than you can ignore your neighbor relentlessly practicing the recorder outside your bedroom window at 6 AM. And that is exactly the point.

Baby on Board

As far as car seats go, the convertible car seat is easy to use. It’s rated for ten years of use, for children who weigh between four and 120 pounds (they also have a SensorSafe infant car seat, for children who weigh between four and 35 pounds).

As befits a car seat that could fit a small adult, it is enormous. It’s 26.5 inches tall and 19 inches wide, and I had to rest while carrying it out to my car. It dwarfs my other convertible car seat, a Britax Marathon. The considerable size might be a factor if your car’s backseat is smaller than a Honda Element’s, or if you need to travel with it.

I mounted it forward-facing for my lanky, 30-pound four-year-old. It’s plush, with head, back, and seat padding that also made it easy to clean various bodily substances—just pull out the extra padding and throw it in the washing machine. The two cupholders are removable, so you can easily wipe off mysterious, sticky snack-grime. (Also, yes, kids are disgusting.)

To install, I threaded the strap through the correct forward-facing path in the back of the seat, used the quick connectors to clip the straps into our car’s LATCH system, checked the level to make sure the seat was sitting upright, and tightened the straps holding the seat in place with the proprietary EasyClick crank.

Once the car seat is plugged in, you download the SensorSafe app on your phone. The app directs you to plug the wireless receiver into your car’s ODB-II port to access your car’s onboard computer. If you’re not a car mechanic, you can plug in the manufacturer, the year, and the model in the app, which will helpfully direct you to where the ODB-II port is.

The SensorSafe app itself is clean and simple. You can add additional SensorSafe devices, add family members, or even switch families (if, for example, you’re an extended family member or nanny). You can check the app to see if the car is moving (hopefully you’re not the one driving) and whether the car seat’s temperature is within an optimal range of 50 to 90 degrees.

The sensor itself communicates to both the wireless receiver and to your phone via Bluetooth and radio frequency. If you're within 30 feet of your locked car and within Bluetooth range, the app warns you that your child is alone in the vehicle for four minutes. If you've left Bluetooth range, the app starts warning you immediately. If you fail to respond, the app will then go on to warn the other people that you've designated as family members, and then emergency services.

Ring My Bell

If stress or fatigue makes you forget your kid in the car, then a smart car seat should make you less stressed, not more. The car seat freaks me out every morning. I don’t leave my kid in the car by herself, but I do sometimes keep her restrained while I’m putting a jacket on my other kid, or leashes on my dogs. In the mornings, the dang thing just doesn’t stop ring-a-ding-dinging.

Every few seconds, there comes another alert on my phone and my smartwatch. Your preschooler is alone in the car—she is not, I’m right here, just trying to pull boots on this toddler—warning! The temperature is too low—I know, it's just for a second, she has a blanket on—critical warning! Please! Stop!

I can’t imagine someone ignoring these notifications long enough for the SensorSafe to alert emergency services. When I tried clipping the buckle on an empty car seat, locking the door, and walking away, the notifications started before I’d walked five feet away, before I'd even gotten back to my front door. Once I got out of Bluetooth range, the app started including a link to the seat's location in Google Maps, just in case I was too far away.

There is no way on God's green earth that you could possibly commute to work, switch off your phone, and not see these notifications. There was, however, one notification that I didn't get that I missed: It would have been nice if the SensorSafe included a weight sensor. The car seat will tell you if the child has unbuckled, but not if you've forgotten to buckle the kid in the first place. Something tells me that relying on a toddler to remind me is probably not a great idea.

For parents who are more worried about leaving their children, there are several failsafes built into the safety system. You're not the only one that the SensorSafe will alert; there are also your family members, if you've designated them, and emergency services. Also, the dongle starts singing its squeaky little song if you stop the car when your child is buckled in, even if your phone is off, or dead.

"It's a pretty in-depth level of security to be added to a product like a car seat," says Amber Stepper, Evenflo's vice president.

Last year, 51 kids died from being left in hot cars, according to NoHeatStroke.org, a site run by Jan Null, a faculty member in the Department of Metereology and Climate Science at San Jose State University. Of all the tragedies that careful parents foresee befalling their kids, this one is eminently preventable. It's not hard to imagine that eventually, most car seats will come with a safety feature of this kind.

Of course, you also have to be willing to tolerate near-constant irritation in pursuit of safety. My body reacts to the dongle's jingle the way that my dogs react to the sound of the mailman’s truck—on high alert, barking nonsensically. No matter where you go, or what you're thinking about, the SensorSafe forces you out of your head for a minute to say, “Wait a second … why does my car sound like an ice cream truck? Where am I? Where is my kid?”

But it does work. Oddly enough, my kid loves it. “Mommy!” she says. “The car is singing to tell you that I’m here!”