The night before James Sissom got married in March, he awoke gasping for air as if there was a plastic bag over his head.

It wasn't pre-wedding jitters, nerves or cold feet. It was because, for the past week, Sissom, 35, had been climbing Mt. Everest with his fiancee Ashley Schmieder, 32, while battling asthma and elevation.

The Northern California couple's elaborate plan to get married on Mount Everest seemed to be fading. Sissom's condition was so bad the couple and their crew almost decided to scrub the mission the day before the couple's wedding day, just feet from the base camp where they were going to tie the knot. A week before, a hiker died from altitude sickness, underlining the severity of Sissom's sickness.

But on the big day, their guide deemed Sissom able to go on, thanks to an oxygen treatment. The couple got married that day at 17,500 feet elevation.

It was a dream fulfilled for the adventurous couple, whose first date was an overnight hiking trip in Yosemite National Park. Schmieder, an executive assistant, became infatuated with Everest after reading Into Thin Air, author Jon Krakauer's telling of a deadly 1996 storm on the mountain. She was a perfect fit for Sissom, a "boy scout with all the gear."

"This was kind of a bucket list trip for us," Schmieder explained. "This is already something we had planned on doing in the future, but not necessarily for a wedding."

The wedding was as much their idea as it was that of their wedding photographer Charleton Churchill, who dubs himself an "adventure wedding photographer."

Schmieder reached out to Churchill on Instagram, where Churchill posts photos of his wedding and engagement shoots featuring couples on cliffs and in Alaskan ice caves.

Schmieder didn't have a destination for her wedding in mind. She and Churchill deliberated. Iceland was considered, but a wedding on Everest was the clear choice. Churchill always wanted to shoot an Everest wedding and had come close one time before.

"Right then it was a home run," said Sissom, a bartender and student. "We didn't even have to think about it. It was like, 'Yes!'"

The group hired cooks, guides and porters to help carry their gear. For nine months, the couple prepared. They bought sleeping bags that could withstand -40-degree temperatures. They hit the gym with cardio, leg workouts and squats to get themselves in shape.

To get to Everest, they took a 15-hour flight from Seattle to Dubai, then to Nepal's capital Kakthmandu and eventually a twin-engine plane brought them to a small airport near the mountain. On March 8, they started climbing, Sissom's suit and Schmieder's light wedding dressing in tow. For the next week, the group braved unbearable freezing temperatures, slippery ice and increasing altitude.

Along the route, the couple stayed in tea houses, small brick buildings scattered along the route. It was so cold at night, and the houses so poorly insulated, they would wake up covered in ice, the result of condensation from their breath freezing.

Despite the cold, both brought their laptops, never fully unplugging. During the trek, Ashley tended to work duties while Sissom wrote papers.

They made it to base camp on March 16, their wedding day. It had been nine days since either showered, seven days since Sissom shaved and eight days of hiking.

"It was the least glamorous wedding day you could imagine," Schmieder recalled.

She packed a bare-minimum make-up kit with just enough foundation for the ceremony and red lipstick. She got ready using a compact mirror. For her hair, she "just winged it," using a bridal belt as a headband to keep the hair out of her face.

It was a small ceremony with Churchill, their two guides, one cook and three porters in attendance. The couple exchanged vows, placed rings on each other's hands and kissed, Churchill said.

"We couldn't believe we were finally there, and exchanging our vows was kind of the cherry on the sundae," Schmieder said. "It was pretty special."

Churchill, who had been with them on the long journey, stood off to the side shooting photos.

"Finally getting down to it was pretty emotional," he said. "What's really amazing, when you're all beat up and cold and tired, it's hard to imagine that you're at the base camp surrounded by the Himalayas."

The couple had memorized their vows on the journey up the mountain, but the elevation made them hard to remember. Sissom said he had to start over three times during the ceremony.

"It was funny though," Ashley said, "and it was memorable."

The couple posed for pictures in temperatures between -5 and 5 degrees Fahrenheit, Churchill wrote on his blog.

Sissom wore a wool suit, underneath he had on wool longjohns. He was still freezing.

"I don't know how she was able to bare her shoulders without any protection," Sissom said.

Schmieder also wore longjohns under her wedding dress. In between takes she would put on a down jacket.

Read more:

The Mount Everest-climbing Snapchatters are going back

Aiming for best-dressed bride? See these new bridal looks

At last, brides can use the restroom without help

"In between photos I would try to warm up," she said. "It was definitely cold and I was just trying to think, 'OK, I'll never get to do this again.'"

In one stunning photo, the couple stands in front of a clearing, James staring afar, Ashley gazing at the camera. Behind them are the frozen mountains dusted with snow among the clouds.

Ashley admitted she was worried how the photos would turn out.

"I didn't feel like the prettiest bride on my wedding day," she said. "I was really blown away when I saw them and I don't know how he made us look like we did."

The ceremony and the photo shoot took just 25 minutes. The group had only an hour and a half at the base camp before their helicopter came to take them down the mountain. Before leaving, the couple wrote their's and Churchill's names on a rock along with the date.

The response to their wedding has been shocking for the low-profile couple. They became overnight celebrities once their intimate photos went viral. Now people are using their wedding as a benchmark.

"We had no idea it was going to be like this," Sissom said. "It's just another crazy experience for us."

Follow Sean Rossman on Twitter: @SeanRossman