The middle of the Bering Sea is not where you want to be when a medical emergency unfolds, as viewers have learned watching the latest arc on Discovery’s Deadliest Catch.

Fans fear Captain Keith Colburn may have experienced a cardiac event while stationed hours away from professional medical care, and the scary moment was documented in the series’ Oct. 1 episode, quickly going viral on TikTok later that evening.

In the video, Keith sat on a bench in the galley with his eyes closed. As he opened them to beckon to his brother, Captain Monte “Mouse” Colburn, they appeared reddened. He whispered to the man, “My left side’s…numb,” and his breath came in choppy gasps. “I can’t feel my arm.”

His brother didn’t seem to believe him at first, replying, “No…you’re kidding,” to which Keith confirmed, “I’m totally serious.”

He offered up a prescription bottle, asking, “Do you want one of these?”

“Yes,” Keith sobbed. “Yes.”

“Come on, man,” Mouse hedged, making Keith even more frantic.

“Mouse, I’m not making this…up,” Keith insisted. “I’m…scared.”

He took the pill and placed it under his tongue after asking how it should be taken. While the clip doesn’t name the medication, it’s presumably nitroglycerin, a medication that can help treat chest pain by relaxing your blood vessels, according to the Cleveland Clinic, and is something typically prescribed to people with coronary artery disease.

Viewers were horrified by the “terrifying” emergency taking place at sea, with many debating whether he was exhibiting symptoms of a stroke, which can include numbness along one side, or a heart attack, which can include pain or numbness in the left arm, particularly in men, as well as a feeling of “impending doom,” which many believed Keith to be experiencing when he expressed his fears.

One nurse who saw the clip emphasized how important it is that “we DO NOT play around with impending doom,” adding, “Omg that’s terrifying 😭 .”

Others were more than empathetic for Keith’s situation, with one writing, “Watching this man break over his health is very heartbreaking. Praying for fast recovery ❤️‍🩹 🥺🫶🏼🙏🏼.”

“This broke me watching Keith admitting he is scared. He is one of the toughest captains out there 💔😢,” another agreed.

“Whether a heart attack or st[r]oke, MINUTES make a difference. You stepped up beautifully,” another declared, while another viewer with medical training expressed concern over how long it would take for help to reach them out on the water when “seconds matter.”