A climber from Newfoundland and Labrador who made it to the top of Mount Everest during a season marked by multiple deaths says he feels that crowding at the final ascent is just one among several safety problems.

Mark Ballard said Monday that when he came to the last portion of the climb there was a chaotic scene of lineups as a number of expedition companies attempted to reach the summit under last week's bright and clear skies in the Himalayas.

Ballard says his Sherpa guide was instrumental in navigating his way through the crowds, especially on the final Hillary Step, swiftly taking him around slower groups and reducing his waiting time in the frigid, thin air.

Still, he said there was a 1.5-hour wait on the way down from the summit due to the queues of climbers lining the route on May 22.

Ballard says he believes there needs to be "work on qualification of climbers" attempting the summit, as he noticed some continued to climb despite difficulties adjusting to the altitude.

He also says some climbers lacked knowledge, such as the protocols when two climbers meet as one is ascending and the other descending on the same rope.

"It was chaos coming down for sure," the Canadian climber said in an emailed comment.

"That (the descent) was all about staying warm, my right foot was freezing."

A photo he provided shows a line of dozens of climbers making their way up and down on May 22.

"I think that part of what happened came down to the smaller weather window this year, which required many companies to push into a small amount of days," Ballard said.

Trevor Day, an associate professor of physiology at Mount Royal University in Calgary, says high altitudes can cause all climbers to lose strength and can lead to sickness -- but inexperienced climbers may not have a strong sense of their own limits.

"If you have experience getting sick and being up there, you have a sense of what you can do and what you cannot do," he said.

The Associated Press has reported a number of May deaths on the world's highest peak, which is about 8,850 metres high and commonly requires about two months of trekking to summit.

Indian climber Ravi Thakar, 28, died during the third week of May while sleeping in his tent at Mount Everest's highest camp site.

An Irish climber, Seamus Lawless, was missing after falling while returning from Everest's summit.

CNN reported that Robin Haynes Fisher died at about 8,600 metres while descending from the summit on May 25, noting he had commented on the overcrowding in his final social media post.

The body of Indian climber Ravi Kumar was spotted on May 20, but it was impossible to retrieve the body, after the climber fell some 200 metres.

Climbers from the United States, Slovakia and Australia also died on the mountain over the May 18-19 weekend.

Everest claims multiple victims each year, often in the "death zone" above 8,000 metres, where the air is too thin to sustain human life.

For example, in 2017, 648 people summited Everest, according to the non-profit Himalayan Database. Six people were confirmed to have died on the mountain that year, one of them on the north side.

Eric Simonson, a partner in International Mountain Guides, said in a telephone interview that his company takes safety measures that include multiple Sherpas carrying additional oxygen tanks when there's a lineup on the final ascent.

"It's just the way the cards got dealt this year .... Unfortunately the weather didn't come good until the very end (of May) and everybody had to go," he said in a telephone interview from the firm's headquarters in Ashford, Wash.

He said on May 22 his company had eight climbers and 11 Sherpas going up to the summit.

"We went up with abundant extra oxygen and manpower .... It wasn't optimal, but I'd rather have people standing in line on a nice day than battling a whiteout."

Simonson said ensuring safety -- whether it be additional Sherpa guides or training of the mountaineers -- costs money.

"The teams that spend the money can create greater safety margins for their customers, and the teams that are bare-boned, they don't have those resources," he said.

The Associated Press reported that the Nepalese Tourism Department issued a record 371 permits this year to people to scale the mountain. The increased number of climbers this year is likely because many people were unable to climb in 2014 and 2015, when deadly avalanches disrupted the climbing seasons.