Updated: Cory Richards Airlifted From Everest

Cory Richards, renowned adventure photographer, National Geographic climbing team member and The North Face athlete, was air lifted off of Everest on Saturday evening after suffering what doctors now suspect to be a pulmonary embolism—a block in anartery of the lungs, often caused by a blood clot. As of yesterday, he was in stable condition in a Kathmandu hospital, where he remains today.

Richards, who is a part of an expedition commemorating the 50th anniversary of the first U.S. ascent of Everest, began to experience shortness of breath on Saturday afternoon at around 23,000 feet. He and expedition leader Conrad Anker returned to Camp 2 at 21,200 feet, where doctors administered supplemental oxygen, initially fearing altitude sickness, but also advised the team to continue down the mountain. At Base Camp, Richards was given blood thinners and lifted to a medical facility in Lukla, Nepal, after a helicopter persevered through "un-flyable" weather to reach him.

Richards and Anker are still hoping to summit Everest via the "risky, little-travelled" West Ridge, as planned—though this is dependent upon Richards' condition.

Get updates at National Geographic, and more in-depth coverage at its On Everest blog

The North Face has released this video of Richards' evacuation