Houston Texans head coach Gary Kubiak, center, his helped after he collapsed on the field during the second quarter of an NFL football game against the Indianapolis Colts, Sunday, Nov. 3, 2013, in Houston. AP Photo/David J. Phillip Houston Texans head coach Gary Kubiak is taken off the field on a stretcher during the second quarter of an NFL football game against the Indianapolis Colts, Sunday, Nov. 3, 2013, in Houston. Houston Texans head coach Gary Kubiak, center, is helped after he collapsed on the field during the second quarter of an NFL football game against the Indianapolis Colts, Sunday, Nov. 3, 2013, in Houston. Houston Texans head coach Gary Kubiak watches from the sidelines during the first quarter of an NFL football game against the Indianapolis Colts, Sunday, Nov. 3, 2013, in Houston. AP Photo/Patric Schneider HOUSTON (AP) - Houston coach Gary Kubiak collapsed leaving the field at halftime of the Texans' game Sunday night against Indianapolis and was taken by ambulance to a hospital. Kubiak hunched over and dropped to his knees at the 24 yard line and was immediately surrounded by medical personnel. He was lifted off the field on a stretcher and taken by cart to the ambulance. The Texans didn't say what was wrong with Kubiak, but did say he didn't have a heart attack. The team said the 52-year-old coach was conscious and was with his family as he was taken to the hospital. Defensive coordinator Wade Phillips took over as coach in the second half. Kubiak's collapse came a day after Denver Broncos coach John Fox was hospitalized in North Carolina as he awaits aortic value replacement surgery. The 58-year-old Fox will have surgery in a few days and will miss several weeks while recuperating. As part of his trip to North Carolina over the Broncos' bye week, he met with his cardiologist in Raleigh and was told to seek medical attention immediately if he felt any discomfort. On Saturday, Fox became dizzy playing golf near his offseason home in Charlotte and was taken to a hospital, where tests revealed he couldn't wait any longer to have the surgery. Kubiak has long been known as a top offensive coach, mentoring quarterbacks in Denver under Mike Shanahan and now Matt Schaub - and Case Keenum - in Houston. Kubiak has had no known public health problems. Kubiak was hired in 2006, along with general manager Rick Smith, after the Texans finished a franchise-worst 2-14. Smith spent 10 years with Kubiak while the coach was offensive coordinator of the Broncos. Smith was Denver's defensive assistant for four seasons before moving into the front office for his last six years with the Broncos. The pair has helped transform the Texans, which began play in 2002, from league laughingstock to contender. The team went 6-10 in their first year and 8-8 in each of the next two seasons. Expectations were high in 2010 after Houston finished at 9-7 for its first winning record in 2009. But the Texans instead fell to 6-10, which led to many fans calling for Kubiak's firing. His original contract was due to expire after the 2010 season, but owner Bob McNair has stepped up to keep Kubiak and defended him several times amid the bumps. Among recent departures were assistant head coach Alex Gibbs (for Seattle) and offensive coordinator Kyle Shanahan went to join his father, Mike, in Washington. Kubiak hired former Denver offensive coordinator Rick Dennison to replace Shanahan and former Atlanta offensive coordinator Greg Knapp to become Houston's quarterbacks coach. Dennison worked on the Broncos' staff during Kubiak's 11 years as Denver's offensive coordinator, and Knapp coached Schaub for three seasons with the Falcons. The highest-profile assistant brought to Houston was Phillips, the veteran son of Bum Phillips and a former head coach in Dallas. Last year, the Texans announced contract extensions for both Smith and Kubiak, rewarding them for taking the team to the playoffs last year for the first time. Kubiak's three-year agreement has him under contract through 2014. McNair said at the time he offered Kubiak a four-year deal, but the coach preferred to make it for three. Kubiak made his mark as Denver's offensive coordinator under Shanahan, winning two Super Bowls. An eighth-round pick out of Texas A&M, he spent nine years as John Elway's backup. He finished his career 4-1 as a starter, all in emergency relief of Elway.