Denver Broncos coach John Fox was hospitalized Saturday after feeling light-headed while playing golf.
The Broncos released a statement confirming that the 58-year-old Fox was taken to a hospital in the Charlotte, N.C., area.
"Denver Broncos Head Coach John Fox was taken to a Charlotte-area hospital after feeling light-headed while playing golf on Saturday," the Broncos' statement said. "He is being held at the hospital for testing and further observation. Our medical staff is currently in contact with Coach Fox, his family and the doctors who are treating him.
"Additional information will be provided as it becomes available."
Fox claimed he is "doing fine" in a text message sent to ESPN senior NFL analyst Chris Mortensen.
"I am doing fine," Fox said in the text message. "We are just running some tests, will know more in a few hours."
Sources initially told ESPN that Fox had experienced symptoms similar to a heart attack. But Broncos executive director of media relations Patrick Smyth tweeted that Fox did not suffer a heart attack.
Talked to Coach Fox a few minutes ago. Did not have a heart attack. Is in good spirits and undergoing additional testing at hospital.
— Patrick Smyth (@psmyth12) November 2, 2013
Broncos officials believe that Fox should be OK, sources told ESPN.
Fox was with a group of friends and family on a golf course near his offseason home when he started feeling dizzy, Smyth said.
The Broncos (7-1), who are on their bye this week, will play their next game Nov. 10, against the San Diego Chargers.
Fox, who is in his third season with Denver, has compiled a 28-12 record with the Broncos.
Denver won the AFC West title in each of its first two seasons under Fox, who also coached the Carolina Panthers to the only Super Bowl appearance in franchise history. He's 107-88 overall, including 6-5 in the playoffs.
ESPN's Chris Mortensen and Adam Schefter and The Associated Press contributed to this report.