If you’re not feeling great, it may not hurt to take a quick look at your Apple Watch. In fact, it saved one builder’s life.

62-year-old Dennis Anselmo was working last August when he suddenly “felt all over the place.” While taking a break, he checked his heart rate on his recently purchased wearable and got some pretty alarming news.

“I was building a fence placing posts in the ground,” Anselmo told The Sun. “I finished lunch at 1:15 and was back to work.

“I felt terrible – like I had a really bad flu. I worked for maybe 10 minutes but said to my helper, ‘I need to sit down.'”

When he checked his Apple Watch, Anselmo discovered that his normally low pulse (he says it’s usually about 50 beats per minute) was a frankly ridiculous 210 bpm, so someone called paramedics. The EMTs said the sky-high pulse might be a sign of a heart attack, so they took him to the hospital, and surgeons operated to clear blockages in his arteries.

“They told me that if I had gone home and gone to bed – as many people do – I would likely have had another, more serious bout in the middle of the night,” Anselmo said. “Those second attacks are the ones that kill. That is a common problem.”

The Apple Watch joined 35 other timepieces in the builder’s collection, but since the heart attack, he doesn’t wear the others anymore.

We’ve heard of the Apple Watch saving other lives, like the teenager whose persistent, elevated heart rate pointed to a potentially fatal condition last September. And with what we know about the Apple Watch’s hidden capabilities and the possibility that the company might add even more health functions in the next version of the smartwatch, we don’t expect we’ve heard the last of these stories.