The volcanic Mt. Lassen Wilderness leads to Hat Creek Rim, a notoriously hot and dry portion of the PCT. Hikers will often travel 20 miles without a reliable water source. I figured that if I was going to be thirsty, at least I could be somewhat cool. I hiked into the night to avoid the sun, camped 10 miles into the rim, and awoke at 5 in the morning to finish the water-less stretch.