Typically, the grunt in this situation will be followed by a couple of deep breaths. Illness. When a baby grunts, it could be a sign of meningitis, sepsis, lung problems or heart failure. This type of grunting is not like the others and it often comes at regular intervals even with each breath.
Longs Peak, a 14,259-foot tall mountain in Rocky Mountain National Park, is one of Colorado's most-climbed fourteeners, and recently one of the deadliest.
Particularly dangerous are tall, easy mountains, notably Kilimanjaro (5895 m) and Aconcagua (6961 m), where it's easy to get dangerously high quickly. Acclimation requires time, and rushing causes altitude sickness. There are other risks at altitude, not covered here.