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DENVER — The Colorado Department of Public Health and Environment issued a Wildfire Smoke Health Advisory for northeastern Colorado on Saturday afternoon.

Officials said the advisory is in effect until midnight Sunday for areas east of the Continental Divide and north of I-70.

Cities affected include Denver, Fort Collins, Greeley, Golden, Littleton, Brighton, Limon, Burlington, Fort Morgan, Sterling, and Julesburg, according to the CDPHE.

If smoke is becomes thick in your neighborhood, experts say you should remain indoors.  People with heart disease, respiratory illnesses, the very young, and the elderly, should be especially careful in these conditions.

Heath experts advise the public to consider limiting outdoor activity or relocating when moderate to heavy smoke is present in your area.

If visibility is less than 5 miles, smoke has reached levels that are unhealthy, environmental experts said.

For more information visit the Colorado Department of Public Health and Environment’s Air Quality information site.