U.S. OpenJune 13, 2016

Jason Day tells Golf Channel he's battling cold as U.S. Open week arrives

DUBLIN, OH - JUNE 04:  Jason Day of Australia waits to hit on the first hole during the third round of The Memorial Tournament at Muirfield Village Golf Club on June 4, 2016 in Dublin, Ohio.  (Photo by Andy Lyons/Getty Images)
Getty ImagesDUBLIN, OH - JUNE 04: Jason Day of Australia waits to hit on the first hole during the third round of The Memorial Tournament at Muirfield Village Golf Club on June 4, 2016 in Dublin, Ohio. (Photo by Andy Lyons/Getty Images)

OAKMONT, Pa. -- Turns out there's something hotter than Jason Day's game and pitching arm:

His body temperature.

RELATED: Watch Jason Day throw first pitch at Pirates game

Day, who's won seven times in his past 18 starts, told the Golf Channel he is battling a cold this week in Pittsburgh. This isn't the first time the 2015 PGA Championship winner has been under the weather at a major: Day dealt with flu-like symptoms at Augusta, where he finished T-10. Day was also sick at Match Play -- remarking he lost 11 pounds over the event -- and missed the Farmers Insurance pro-am because of similar issues.

Day enters Oakmont Country Club as the world's No. 1 player and the Vegas U.S. Open favorite.


WATCH: GOLF DIGEST VIDEOS