Travis Chalmers, of Elmsdale, Nova Scotia, Canada, said that he was outside playing road hockey with his son when he suddenly experienced a “warm sensation” in his chest area and a splitting headache.

“I just thought it was a flu or cold coming on and my seasonal allergies had been kicking in. I thought it was flu-like symptoms and shrugged it off,” he said.

The watch indicated that he was experiencing atrial fibrillation, a rapid heart rhythm that can increase the risk of stroke and heart failure. As his heart continued to maintain an irregular pace, he decided to head to a nearby hospital.

“When I said atrial fibrillation and gave them the symptoms, I was rushed right in,” he said.

Chalmers, who’s 44 years old, said doctors confirmed there were high troponin levels in his blood, indicating damage to the heart. After several tests, it was confirmed he was experiencing a heart attack.

“I stayed in the hospital for a week and got more tests done to confirm and one of my arteries is 100 percent blocked,” he said, adding that the blockage likely occurred while he was playing road hockey with his son.

Chalmers will require daily medication for the rest of his life. He credits the Apple Watch’s monitoring capabilities for detecting irregularities against his usual heart rate.

“Basically, it tells you something is different from what it’s been monitoring before, and if this is out of character for you, see a medical practitioner immediately,” he explained.

Chalmers is a firefighter with an active lifestyle and a limited family history of heart problems, so the whole incident came as a surprise.

“It’s one of those things, you just don’t know what’s going on inside. It can hit anyone at any time,” he said. “I’m very fortunate the watch gave me a second set of eyes.”

For more on this, read the full Global News report.