There are plenty of reasons the trek up Mount Everest is grueling and unpleasant: the low oxygen levels, the bitter cold, the dangerous terrain. Add one more unlikely headache to that mix: piles of human excrement, everywhere. Mount Everest has a huge problem with human feces, and it's only getting worse. Littering every one of the four sleeping areas, as well as on the way up the peak, are mounds of poop left by hikers over the years. Many climbers believe the weather conditions on Mount Everest will keep it clean, but that's not the case. One problem for hikers is that melting snow to drink water will likely yield in feces-contaminated water.