Country icon Willie Nelson had to cut short a concert in Salt Lake City Sunday after suffering respiratory issues.
The 84-year-old singer later took to twitter to tell fans, "The altitude just got to me."
The 20,000-capacity USANA Amphitheater is located in West Valley City, Utah, a suburb of Salt Lake City, with an altitude of 4,300 feet.
The tweet posted after the concert read: "This is Willie. I am very sorry to have to cut the Salt Lake City performance short tonight. The altitude just got to me. I am feeling a lot better now and headed for lower ground."
Texas-born Nelson has recorded more than 60 albums, written songs such as "Crazy," and appeared in more than 30 movies and TV shows.
Known for his honky-tonk tunes and hippie flair, Nelson rose to prominence in the late 1960s and early 1970s. His fame has transcended genres with the release of hits such as “Always on My Mind” and “On the Road Again,” in the 1980s.
Both songs peaked within the Billboard Hot 100, and throughout his career Nelson has had 20 No. 1 hits and 114 chart singles, according to the Country Music Hall of Fame. The Billboard charts rank Nelson as the No. 3 greatest of all time country singer after George Strait and Merle Haggard.