After Apple’s event this past Monday, I wrote up some high-level thoughts on the company’s announcements, and I focused on why I have so much faith in the underlying good Apple is doing. Contributions to the arts, environment, and technology that will have a lasting positive impact on all our lives down the road. But there’s another area where Apple’s efforts to improve our wellbeing are already having a major impact, and I experienced firsthand just how important Apple’s work in this crucial area truly is.

I received a text message from my mother at about 3:30AM this morning saying that my father was at the hospital. Less than an hour earlier, his Apple Watch Series 4 alerted him that Atrial fibrillation had been detected. Apparently, he fell asleep with his Apple Watch on and woke up in the middle of the night with some chest discomfort. Figuring that the Apple Watch was already on his wrist, he checked his heart-rate, which ended up being elevated compared to his normal resting heart-rate. He then decided to do an ECG using the ECG app. And then another. And again another. Every time he put his finger on the digital crown and watched as the Apple Watch ran an electrocardiogram, it came back with the same message: Atrial fibrillation detected. He woke my mother up, and went right to the hospital.

After arriving at the hospital, the personnel there performed an ECG and confirmed that he indeed was having Atrial fibrillation. Not only did the hospital’s ECG reading show it, but my father — because he is my father — ran the ECG on his own Apple Watch to double-check, which also showed Atrial fibrillation as the hospital’s test was being run.

A couple of hours later, after seeing his cardiologist, he is now wearing an at-home heart monitor for two weeks, and is on some light medication. His doctor also mentioned he was the second patient this week to come in after the Apple Watch detected AFib, and the first patient was also not a false-positive. Thankfully, my father should be fine and hopefully will continue to pester me with technology questions for years to come.

This is exactly the kind of outcome that Apple intends at this point in time — the Apple Watch isn’t something to diagnose you or replace your doctor. It’s a tool that enables you to have more insight into your personal health, and it can help alert you to potential health problems. While my father was proactive in opening the ECG app on Apple Watch, the device also passively checks for irregular heart rhythm including low, high, and atrial fibrillation. It can not detect all instances of irregular heart rhythm in the background, but it’s incredibly comforting to know that tens of millions (or more) of these devices are working in the background to alert people to these potentially life-threatening occurrences.

When the Apple Watch was first announced, there might not have been a bigger proponent. You might even say I took the gold. And this story above is exactly why I had those initial feelings on this new device category that Apple has created. It’s what I, and others, envisioned would eventually happen. We have moved from notifications, convenience, and style to an indispensable product where there is actual risk involved with not wearing it. I firmly believe it’s that big of a deal. I couldn’t imagine not using Apple Pay on my wrist. Not using it to track my workouts and compete with my friends. Not using it to effortlessly reply to messages and notifications. Not using it to track my activity and heart health. And my father wholeheartedly agrees.

Thank you, Apple.