DENVER — A large brown cloud has been hovering over metro Denver for several days. The phenomenon is also known as an inversion, when cold air is trapped underneath warmer air. The poor air quality has caused some to experience allergy symptoms and breathing problems.

FOX31 and Channel 2 meteorologist Matt Makens said the haze is filled with pollution, humidity and dust.

“You’re looking at the layer of cold that’s holding a lot of garbage,” Makens said.

Dr. Monique Butler, chief medical officer at Swedish Medical Center, said the pollutants can be a trigger for many allergies and worsen conditions like asthma and chronic obstructive pulmonary disease (COPD).

Butler says it’s important to seek help if you experience a shortness of breath and chest pain.

“(If there’s) heaviness in your chest and you’re just not feeling your best, you want to have a low threshold — especially during this time of smog — for seeking out a physician,” Butler said.

She emphasized that children and the elderly can be at an increased risk. More information about Swedish’s allergy center is available on the hospital’s website.