Should you wear a mask? Advice for protecting yourself as Illinois air quality worsens

Experts warned people to stay indoors when possible and consider wearing masks as Chicago's air quality reached unusually poor levels Tuesday.

According to some, even just minutes outside could impact your health.

But what is the best thing to do to protect yourself?

The conditions have already led to an air quality alert, forced cancellations of flights and events across the region and prompted the closure of several outdoor facilities in both the city and suburbs. An air quality alert is in effect until at least midnight for the region.

"We have these wildfires, we have this heat, we already have environmental air pollution - so the combination is kind of like a perfect storm," said Dr. Whitney Lyn, a family medicine physician with Cook County Health.

According to the government air quality website, AirNow, the PM2.5 -- an air pollutant also known as fine particulate matter, which is causing much of the haze in the region -- reached 258 as of 4 p.m. Anything over 200 is considered "very unhealthy" and once the region reaches above 300, it enters a "hazardous" level.

“The EPA index of 20 is equivalent to smoking one cigarette a day,” Dr. Ravi Kalhan, deputy division chief of pulmonary and critical care medicine at Northwestern Medicine, told NBC Chicago. “Today, the air quality index in Chicago has been approaching 200. That’s like smoking a half-a-pack of cigarettes a day.”

Here's how you can protect your health from the smoky haze:

If you go outside in smoky conditions, consider wearing a mask, like an N95, to protect your lungs. The mask should fit over your nose and under your chin, and seal tightly to your face to keep out the smoky air.

Washington health officials said “respirator masks may provide some protection by filtering out fine particles,” but they warned that any hazardous gases found in smoke will not be filtered out.

Still, the best mask, experts agree, is an N95 respirator, as they are the easiest to find and the cheapest to buy.

Residents who are buying such a mask should make sure that they are certified by the National Institute of Occupational Safety and Health, and should be sure that the mask has two straps that go around the wearer’s head.

Residents should also be sure the mask fits snugly over their nose and mouth, and it should go under the user’s chin.

Federal officials say that masks should especially be worn by those who have to spend extended periods of time outdoors.

Chicago's mayor urged people to consider wearing masks Tuesday.

"For additional precautions, all Chicagoans may also consider wearing masks, limiting their outdoor exposure, moving activities indoors, running air purifiers, and closing windows," Mayor Brandon Johnson said in a statement. "As these unsafe conditions continue, the City will continue to provide updates and take swift action to ensure that vulnerable individuals have the resources they need to protect themselves and their families."

The city's top doctor also noted that N95 or KN95 masks were encouraged.

"Those can help," Chicago Department of Public Health Commissioner Dr. Allison Arwady said. "You don’t want surgical masks. They’re not going to help particularly with smoke. There is a lot of particles in the air that are less than 2.5 microns. They’re smaller than respiratory droplets. Anything that is covering your nose and mouth can help from a viral perspective. When you want to keep particles out, you really do want to wear one of the N95 or KN95’s.”

According to the American Lung Association, "N95 respirators are designed to protect workers all day in a dusty environment, so eight hours is a good general rule."

"OSHA wants those workers to use a new N95 every day. People should store them properly if they are going to re-use them and not hang them from the elastic band," the group said.

Here's what officials recommend when levels reach the "very unhealthy" status.

People with heart or lung disease, older adults, children and teens:

Everyone else:

STAY INDOORS

The small particles in wildfire smoke can irritate the eyes, nose and throat, and can affect the heart and lungs, making it harder to breathe. It’s important to limit outdoor activities as much as possible to avoid breathing in these particles, health agencies say. You should especially avoid strenuous activities like going for a run, since heavy breathing will increase the amount of smoke you inhale.

"If you have any type of underlying lung condition… we would like you to stay inside," Lyn said. "If you do need to go outside, keep time outdoors limited… if you’re outdoors we want you to keep you mask on."

And bring pets inside too: Animals are also affected by smoky conditions.

KEEP INSIDE AIR CLEAN

When inside, keep doors, windows and fireplaces shut so that smoke stays out. If you have a portable air purifier or HVAC system, run it to help keep the air clean, the Environmental Protection Agency recommends.

Check that your filters are high quality and up to date. Make sure any filters or air conditioners are set to recirculate indoor air to avoid bringing in smoke from outside. If you have a window air conditioner, check that it's sealed to the window as tightly as possible. And try to avoid activities that would add more particles to the air in your home — like smoking, burning candles or frying meat.

"Make sure air filters cleaned, make sure HVAC systems clean," Lyn said.

WASH UP

Dr. Juanita Mora with the American Lung Association said things like showering, changing clothes and doing saline washes could help.

"One thing you can do is nasal saline washes, which helps to flush out" she told NBC Chicago. "I'm also recommending that after people have been outdoors, coming in, taking a shower and changing our clothes, because we have that particulate matter and smoke all over our clothes and in our hair - everything.”

KNOW YOUR RISK AND WATCH FOR SYMPTOMS

Some groups should be extra careful as they face higher risks from wildfire smoke. Children and older adults are especially sensitive to smoky conditions. Those with health conditions affecting the lungs or heart — like asthma or chronic obstructive pulmonary disease — face higher risks from poor air quality, along with those who are pregnant, according to the Centers for Disease Control and Prevention. People in these groups should take extra precautions and monitor for symptoms like coughing, trouble breathing or fatigue.

"Any chest tightness, dry cough, any irritation of the eyes or irritation of the throat… contact your doctors about any of these symptoms of pollution,” Mora said.

List of symptoms to watch for: