So tomorrow morning my wife and daughter fly out to Denver. It will be their first time visiting there. My wife made the mistake of reading about altitude sickness in the town (evergreen) they are staying in. I believe its roughly 7000ft ASL. She is now getting anxious because the article mentioned visitors having difficulty breathing. I told her at 40 yrs old she should be fine, but its already in her mind. I'm sure many in here have visited Colorado, an was wonder if you had any issues or tips for it. Thanks