SALT LAKE CITY - Comedian and "30 Rock" cast member Tracy Morgan is back at work in New York after a brief hospitalization in Utah.
Morgan's publicist, Lewis Kay, says Morgan appreciates fans' concern. The actor was hospitalized Sunday while attending the Sundance Film Festival in Park City, where the elevation is 7,000 feet.
Kay says Morgan suffered from exhaustion and altitude. Morgan also has diabetes.
Kay says no drugs or alcohol were found in Morgan's system.
Recordings of 911 calls made on the night he collapsed, and obtained by The Associated Press, indicate Morgan passed out at the Blue Iguana restaurant.
One caller says he didn't know if the actor had been drinking, but said he was unconscious. An ambulance later took him to a nearby hospital. He was released a day later.