Transcript for Deaths on Mount Everest raise safety concerns

Now to growing safety concerns on mt. Everest after four more people were recently found dead on the world's highest peak. A record number of climbing permits have been issued this year raising fears that number could climb. ABC's Linzie Janis is here with more on that. Good morning, Linzie. Reporter: Good morning. This year's climbing season isn't over yet and already it's shaping up to be more deadly than average. One big problem this year, it's crowded up there. This morning, the world's tallest mountain claiming the lives of four more climbers. Their bodies found in a tent just 3,000 feet from the summit in an area known as the death zone where oxygen measures at one-third of Normal levels. The conditions there are very harsh. Ten to 25 below zero with steady winds over 60 miles an hour. Reporter: The number of victims so far this year, now ten including 50-year-old Alabama doctor Roland Yearwood who died last weekend succumbing to altitude sickness. One of Everest's biggest killers. Algside frostbite, falls and avalanches. Yeah. Reporter: Like this one in 2015 triggered by an earthquake killing 19. Hurry. Reporter: But there is another killer on Everest, a man-made one. Experts say overcrowding is making the mountain more dangerous than ever. Leading to incredible scenes like this one in 2012 showing a giant human snake of climbers. The dangers that you're going to deal with when you're in a giant line like that if there's any problems with the climbers ahead of you, you could be in the line of fire. Reporter: David kaviny has flown 50 rescue missions this year alone. Over 700 folks actually climbing. Reporter: While other helicopters are flying in luxury. Some climbers even reportedly indulging in champagne breakfasts. There are some better creature comforts, television up there, there's wi-fi there. I know that some guiding ex-pe digs will wake you up and bring coffee to your tent. Reporter: There was a deejay party at base camp in April. It's pretty much wide open on Everest as far as who can climb the mountain. Pretty much anybody with a checkbook can go up there these days. The problem with crowds on Everest is you move up the mountain more slowly increasing your chances of fatigue and frostbite and costs up to $70,000 to climb. You couldn't pay me to do it. All right. Joining us is Dr. Kenneth Kamler the author of "Surviving the extremes." He was the only doctor on the mountain during the 1996 disaster when eight people lost their lives. Thank you very much. I enjoyed reading your book. Tell people what it is about mt. Everest that people want to conquer? I think everyone needs to have some goal that they feel is nearly impossible or almost beyond their reach because that brings out qualities in people that they never knew they had and would otherwise lie dormant their entire lives so taking on a challenge like that brings out the best in people and climbing, I think, especially, because it reduces life to its essentials. You worry about staying warm, about shelter, food, friends, really understand what's important in life and you keep that with you when you come back from the mountain. You understand that it comes at great risk and not just the weather, avalanches, but just explain what that altitude does to the body. Altitude is not natural to the body. No one lives at that kind of an altitude. The body can't acclimatize to an altitude higher than 18,000 feet. Beyond that your body just deteriorates. Near the summit of Everest you only have one-their as much oxygen as you have at sea level so your body doesn't have enough oxygen to burn its inner fire so metabolism slows down and you lose energy and think clearly and that leads to secondary problems. Do you think as we saw in the piece that -- I even said to you, the reason I hesitate. I considered it for my 50th and said for all the reasons that you described and I'm thinking, my goodness, I have no experience or are there too many permits that are being issued? Yes, there are far too many perpendiculars being issued. I remember when I was up near the summit there were nine of us. We were the only group up near the summit. The only one and now I see pictures lines of people waiting to go up to the summit. Everest has enough dangers as it is, you don't need to add additional danger of waiting in line and freezing to try to get up toward the summit so it does make it more danger. Those inexperienced people put others at risk, don't they. They certainly do. Number one, too many people altogether and number two, Everest has become a trophy for a lot of people. They're not really mountaineers and just sort of want to grab that trophy and they're not really qualified to be there in the first place. You shouldn't attempt Everest unless you've done a lot of other mountaineering and proven yourself you can do that relatively safely. You want to do it again. I've been there six types. One time I was 900 feet from the summit and we turned around because of really bad conditions and I'm satisfied with that. I think I got what I needed and I really don't need that last 900 feet. Good for you. Glad you're here. Thank you very much.

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