Hallucinations are a serious sign of altitude sickness, specifically high-altitude cerebral edema (HACE), where the brain swells due to a lack of oxygen, according to the Cleveland Clinic.

HACE affects less than 1% of people who reach an altitude of 13,000 to 18,000 feet above sea level.

This is what they didn’t account for. It’s already a rare condition, and one that only a few people will ever find themselves in a situation to discover they have it. Poor guy. I hope he recovers okay.

Hiked up Whitney a long time ago with my then-girlfriend. She got altitude sickness about 2/3 way up, even though we had been careful staying overnight at the halfway point to acclimatize. She couldn’t wake up and get out of the tent. Wouldn’t eat or drink. I was worried about embolisms. We had to turn and head back down. It was pretty scary.

Read Krakauer’s Into Thin Air. You don’t want to mess around with altitude.

My god, even if that kid survives that father is going to be traumatized the rest of his life. It has to be so hard not to blame yourself for something like this. :(

This is scary. I had no idea this is a thing. Poor boy. He seems like such a nice kid too. :(

Zane Wach is now in a medically induced coma from the fall on Mount Whitney in the Sierra Nevada mountain range on June 10 that left him with severe head trauma, as well as a broken ankle, finger and pelvis