A satellite image from space at NASA’s Jet Propulsion Laboratory tells the story: Massive plumes of thick, white smoke emanate from the Los Angeles area and stretch east across California, toward states such as Colorado, 1,000 miles away.

The smoke and particles are responsible for the orange haze that’s been hovering over the state for several days, and it just might make you wheeze. So says the Colorado Department of Public Health and Environment, which has issued a health advisory, according to several news organizations along the Front Range, including Longmont’s Daily Times-Call.

As Pat Reddy, a meteorologist with the department’s Air Pollution Control Division warns (via The Denver Post), “When smoke is thick or becomes thick in your neighborhood, remain indoors. This is especially true for those with heart disease, respiratory illnesses, the very young and the elderly.”

Runners are feeling the effects, too.

“I thought maybe I decided [that] I started smoking in my sleep or something, I wasn’t quite sure why my lungs are so sore,” Niki Breigenzer tells 9News. “I’m almost to five miles, which usually isn’t this hard for me as it is today.”

The smoke is expected to diminish tonight, but officials will have to evaluate to be sure. After all, there are several fires burning in the west, including in Utah and smaller blazes in Colorado.