Climbing Mount Everest is cool, but it can also make you temporarily insane

While climbing Mount Everest can be one of the coolest things you do in your life, it can apparently also make you go completely insane.

Published in the journal Psychological Medicine, researchers found that mountaineers traveling at extreme altitudes can experience psychosis, with symptoms including hallucinations and delusions.

In 2008, one climber reported hiking the Himalayas all day with a hallucinated man named Jimmy who spoke words of encouragement to him and then vanished, according to Fox News.

This new degree of altitude sickness dubbed “isolated high-altitude psychosis” may be its own medical condition.

However researchers aren’t really sure what actually causes it and say it may be just as much a result of climbing alone as it could be related to high altitudes.

The symptoms occur once mountaineers reach heights greater than 22,965 feet but seemingly disappear completely once they get out of that danger zone.

The research could help further advancement on temporary psychosis in general.