Wednesday's eight-race program at Churchill Downs has been cancelled because of excessive heat in the Louisville area. A National Weather Service excessive heat warning for Louisville remains in effect until Wednesday at 9 p.m. ET. Heat index values of 105 to 109 are forecasted for Wednesday. Cancellations of races at Churchill Downs because of weather conditions are rare. Wednesday's cancellation was the 22nd in track history and only the second related to extreme heat, joining June 28, 2012. Racing at Churchill Downs is scheduled to resume Thursday at 5 p.m....