An 89-year-old Boulder County man is Colorado's third confirmed West Nile virus fatality of the 2007 season.

The man first became sick around July 5, said Heath Harmon, communicable disease division manager for Boulder County Public Health.

"This is a very unfortunate reminder of just how potentially serious WNV infection can be and why residents should continue to take precautions against mosquito bites," Harmon said.

Officials urge Coloradans to continue to wear mosquito repellant with DEET and to wear long sleeves outdoors during dawn and dusk, the prime hours when female mosquitoes are seeking blood meals in order to lay eggs.