01/23/2012 at 01:00 PM EST
Tracy Morgan was rushed to hospital in Park City, Utah, on Sunday after collapsing at the Sundance Film Festival, according to reports.
The 30 Rock
actor, 43, fell unconscious following the Creative Coalition Spotlight Awards dinner, where he accepted the Spotlight Initiative Award, according to the Hollywood Reporter.
He was taken to Park City Medical Center.
"Superman ran into a little kryptonite. The high altitude in Utah shook up this kid from Brooklyn," Morgan Tweeted
on Monday. "Thank U 2 the hospital staff. Back at work 2morrow shooting 30 Rock. Holla at me!"
A spokeswoman for the hospital said no drugs or alcohol were found in his system. The actor's rep denied Morgan had been drinking, despite reports that said he seemed out of control at the dinner, yelling and falling down.
In a statement, the rep said Morgan was hospitalized "from a combination of exhaustion and altitude, Tracy is seeking medical attention," adding: "He is with his fiancée [Megan Wallover] and grateful to the Park City Medical Center for their care. Any reports of Tracy consuming alcohol are 100% false."
Morgan's current status was not known. The outspoken (and often controversial
) actor, who has diabetes, underwent a kidney transplant
in December 2010.