A fit professional firefighter is crediting his Apple Watch for helping to save his life when he suffered a heart attack after playing road hockey with his son.

During the game, Travis Chalmers of Elmsdale, Nova Scotia said he suddenly felt a "warm sensation" in his chest, along with a splitting headache. At first, he thought it was a flu or cold coming on and "shrugged it off," he said.

"About a half hour later, I'm laying down with my daughter and my heart rate is still beating out of my chest," he told Canada's Global News. He then glanced at his Apple Watch, which told him he was experiencing atrial fibrillation.

While the Apple Watch cannot inform wearers if they are having a heart attack, it will notify wearers of sudden changes in heart rate, called atrial fibrillation. Such warnings should prompt users to seek medical attention.

Chalmers continued to monitor his heart rate over the next few hours. After continued warnings from the Watch of irregular heartbeats, he decided to go to the hospital.

"When I said atrial fibrillation and gave them the symptoms, I was rushed right in," he said. "That's when they told me I'm probably having a heart attack."

Patient and doctor credit Apple Watch for giving timely life-saving warnings

Doctors confirmed high troponin levels in his blood, a key indicator of heart damage. Chalmers said that his doctors told him one of his arteries was 100 percent blocked, with that triggering the beginning of the heart attack while he was playing road hockey with his son.

Chalmers, a father of two who has an active lifestyle, was surprised by the diagnosis — although his family has a limited history of heart disease. "It can hit anyone at any time," he noted.

"I'm very fortunate the Watch gave me a second set of eyes," he added in crediting the Apple device for the alert. Chalmers noted that wearing it routinely over a prolonged period of time enabled it to alert him of his sudden heart rate irregularities.

He will now need to be on medication for the rest of his life. Chalmers was released from the hospital after a week, and will soon be able to resume his normal life activities.

Cardiologist Ciorsti MacIntyre of Halifax's QEII Infirmary noted that while readings from smartwatches and other health devices aren't always as severe as indicated, it helps patients be more aware of possible problems, and seek medical attention earlier than they otherwise might.

Devices like the Apple Watch can help doctors "reconstruct what was going on to allow us to correlate their symptoms with what the heart rhythm might be doing at that particular time," MacIntyre said. "We can't be with people 24/7, [but] the watch can be."

For his part, Chalmers is grateful he had the Apple Watch to confirm that something more than "feeling unwell" was going on.

"This was a really bad situation. If I didn't come in, there's a chance I wouldn't be here," he said.