Yes I found out the hard way about needing oxygen. It ruined my art workshop. My heart pounded even during the day. It was like someone was jerking the sleeve of my shirt 24 hours a day. I am a low land gal, the mountains are beautiful but no more.
I have been on many hunting trips to New Mexico, Colorado, Wyoming but for some reason the altitude gets to me now. Could it be my advancing age? LOL!
If you ever have to go to altitude ever again, try taking Gingko Biloba beforehand.
The rumor is that it very slightly allows red blood cells to carry a little bit more oxygen, and that little bit can make all the difference!