Fortunately, as we rose higher, there were no more crevasses, but I began to feel a curious exhaustion that I had never experienced before. At sunset the thermometer which Kachi carried for me had descended forty degrees within a few minutes, and the sudden change in the temperature seemed to affect us all more or less; but we went on, with the exception of Bijesing, who was seized with mountain sickness so violently that he was unable to proceed. The doctor, too, a man of powerful build, was suffering considerably. His legs, he said, had become like lead, and each seemed to weigh a ton. The effort of lifting, or even moving, them required all his energy. Although he was terribly blown and gasping for breath, yet he would not give in, and he struggled on bravely until we reached an altitude of 20,500 feet. Here he was seized with such exhaustion and pain that he was unable to proceed. Kachi Ram, the Rongba and I went ahead, but we also were suffering, Kachi complaining of violent beating in his temples and loud buzzing in his ears. He also gasped and staggered dangerously, threatening to collapse at any moment. At 21,000 feet he fell flat on the snow. He was instantly asleep, breathing heavily and snoring raspingly. His hands and feet were icy cold, and I rubbed them. But what caused me more anxiety than anything was the irregular beating and throbbing of his heart. I wrapped him up in his blanket and my waterproof, and, having seen to his general comfort, I shouted to the doctor, telling him what had happened, and that I was going to push on as much higher as I could stand, the Rongba being now the only one of the party who was able to keep up.