Lukas Furtenbach, a famous mountain guide, led a British team on a very fast climb of Mount Everest. They used a special gas called xenon to help them. The team left London on May 16th, reached the top on May 21st, and returned home two days later. This xenon gas treatment is designed to protect climbers from getting sick at high altitudes. However, it has caused some debate and is now being investigated by Nepalese climbing officials. The climbers prepared for the climb by training in special tents that simulate high altitude conditions and by having xenon gas treatment at a clinic in Germany. Furtenbach believes that spending less time on the mountain could reduce environmental damage, for example, less human waste. He also states that the xenon gas was never actually used in Nepal, and he can prove it is safe for climbers.