Lukas Furtenbach, a well-known mountain guide, led a British team on a very fast climb of Mount Everest. They used a special xenon gas treatment. The team left London on May 16th, reached the top on May 21st, and came back home on May 23rd. This xenon gas treatment, which is meant to help climbers avoid altitude sickness, has caused some disagreement and is now being looked into by Nepal's climbing authorities. Before the climb, the team got ready by training in special tents that simulate high altitude and by having xenon gas treatment at a clinic in Germany. Furtenbach believes that spending less time on the mountain could help the environment, for example, by reducing human waste. He also stated that the xenon gas treatment was not done in Nepal, and he is confident he can show it is safe for climbers.