I grew up in Pueblo, with the family ranch 60 miles away at 8,000 feet. Yes, I could tell the difference when I went up, but not as bad as now when I go back from Nebraska. With a week in Pew-town, you'll be fine.

Oh, and don't forget sunscreen. The sun can be fierce at those altitudes. (Use it, don't just take it like some dummy you know. )