Lukas Furtenbach helps people climb mountains. He helped a team from Britain climb Mount Everest very fast. They used a special gas called xenon. The team left London on May 16. They climbed the mountain on May 21. They came home two days later. Some people do not like the xenon gas. It helps climbers not get sick when they are high up. Nepal is checking if it is okay to use. The climbers trained in special tents. They also used xenon gas in Germany. Furtenbach says climbing faster is good for the mountain. He says they did not use the gas in Nepal. He says it is safe for climbers.