NBC News' Morgan Chesky Hospitalized After Almost Suffering Cardiac Arrest

NBC newscaster Morgan Chesky has a word of caution for hikers.

On April 26, the Dallas-based Emmy-winning journalist shared an Instagram post that detailed how a hike at Zion National Park resulted in an emergency visit to the hospital.

"I’ve never shared a story quite like this one," Chesky wrote. "It's an odd feeling to walk out of ICU. Less than 24 hours after soaking up views at Zion National Park, I was in the back of an ambulance, on oxygen, with no idea what was wrong."

Chesky went on to share how his "painstakingly planned" adventure included a hike at Bryce Canyon and a trip to Zion the next day with a "legendary crew." According to Chesky, things began to take a turn when he was hit with a sudden fever after the hike at Bryce Canyon.

"I thought a good sleep would be enough, but a few miles into the hike at Zion, I grew frustrated," he added. "I couldn't seem to catch my breath."

Chesky further pointed out that he's hiked "tougher trails at higher elevations" in the past, but even keeping a slow pace during this trip made his pulse spike.

"I got angry. When my uncle grabbed my pack, I let him take it and finished the trail, too weak to even celebrate," he recalled "I popped Tylenol, determined to sleep it off again. But when I woke up worse, I caved. After hearing my symptoms at Urgent Care, they tested my pulse ox (blood oxygen saturation). Normal is 95-100 percent. Mine read 58."

The startling number made Chesky's group decide to call for an ambulance, which took him to Cedar City Hospital. There, a CT scan showed that fluid was filling the journalist's lungs.

"A blood test showed my heart was stressed, and I first heard the term HAPE High Altitude Pulmonary Edema," he explained.

According to the National Institute of Health, high altitude pulmonary edema is a "noncardiogenic pulmonary edema which typically occurs in lowlanders who ascend rapidly to altitudes greater than 2500-3000 m."

"I was confused. I’ve hiked at 14,000 ft," Chesky explained. "These hikes barely broke nine. Doctors told me it didn't matter. A cold I may not have noticed in Dallas was exacerbated by elevation, making me even more prone to altitude sickness. When my lungs started to fill with fluid, it forced my heart to work harder, causing my pulse to skyrocket."

According to Chesky, staff explained that the condition could lead a person to "pass out from lack of oxygen" or go into cardiac arrest.

"Hard pass," Chesky commented of the possibilities, before writing that after "over 24 hours, high flow oxygen, blood thinners, and stellar care eased me back towards a safe baseline. My best night's sleep in days was in an ICU bed I felt lucky to have."

Chesky concluded his post with a thank you to the staff of Cedar City Hospital, calling them "the best."

"To my uncles who knew something was wrong and stuck w/me, don't expect to carry my pack ever again," he quipped. "And to the crew who had my back throughout this scary-as-hell ordeal, much love. I’m not home yet, but hope to see y’all at a lower elevation soon."

In the comments section of Chesky's post, fans wished the correspondent a quick recovery.

"Thank god you’re ok & hopefully, the next hike will be less exciting!" one user replied.

"That is bananas!" another wrote. "So glad you are ok. Pretty frightening lesson. Take it easy."

Alex Portée is a senior trending reporter at TODAY Digital and is based in Los Angeles.