CHICAGO -- Home-plate umpire Paul Nauert was unable to finish Sunday's 8-7 Reds win over the Cubs, exiting after 7 1/2 innings because of a heat-related illness.

The game-time temperature was 84 degrees at Wrigley Field, and it was humid. A few fans in the crowd of 39,619 had to be treated, as well, for heat-related problems.

The Cubs' athletic trainers attended to Nauert between innings throughout the game with wet towels and provided water and Gatorade. First-base umpire Doug Eddings took over for Nauert behind the plate.

"It gets hot here, it gets humid here," Cubs manager Mike Quade said. "I hope he's OK."

A spokesman for Major League Baseball said Nauert was day to day.