By Meredith Lepore
Apr 15, 2016 @ 10:00 am

When you are busy working parents with three small children, enjoying a little alone time on a relaxing vacation can be a smart move. However, Chris Hemsworth and his wife Elsa Pataky recently opted for the opposite type of getaway: The star duo took a trek up the Himalayas and things were not so easy.

The Thor actor came down with altitude sickness that completely altered his personality, he said on Thursday's Jimmy Kimmel Live! "We got higher and higher and ended up about 4,000 meters [over 13,000 feet​] above sea level," the Australian star said, and then he started to slowly "lose his mind" and become "completely irrational and oversensitive to the most trivial, silly things." Hemsworth posted a picture of his trip to the Himalayas (below), before things took a scary turn:

My local Himalayan guide directing me to the top, 3700m above sea level !!

A photo posted by Chris Hemsworth (@chrishemsworth) on

During one night, the actor's breathing got so bad that he started to sound like "Darth Vader meets Daffy Duck," Hemsworth said. When that happened, Pataky ran to get the guides, who said to immediately get him off the mountain. And he took an eight-hour helicopter ride down the mountains.

Though The Huntsman: Winter's War star can laugh about it now, he realizes how serious it was. "The oxygen was in my lungs and the next stage was oxygen in my brain and then—good night. We wouldn't be sitting here," he told Kimmel, who said: "Maybe it's because you're handsome. You're not meant to be up in the mountains, you're meant to be amongst the people bringing joy to their eyes." We would agree. Stay down here Chris!

Watch Hemsworth talk about his vacation in the clip above.