Dozens of wildfires continue to burn across the northern coast of Massachusetts and across the state. Firefighters will return to active areas on Tuesday to try to extinguish the flames.

The fire chief said more than 250 hectares were burned here in Middleton yesterday in a bushfire that has spread to North Reading.

You could see the smoke over Middleton Pond Tuesday morning as several areas in the forest were still actively burning.

But at this time, these flames are not endangering any homes in the area.

Hundreds of acres are burning in Massachusetts

Firefighters drove around Tuesday morning to monitor the fires. They will be active again to extinguish hotspots as soon as the sun rises and visibility improves.

On Monday, helicopters hovered over the pond and grabbed buckets of water to dump on the flames.

A similar operation will take place Tuesday morning in Canton, where another wildfire is burning.

And firefighters in Salem, Lynn and Peabody will continue to battle a 300-acre wildfire that has spread through those communities.

Douglas LeColst, the fire chief in Middleton, said these fires are too big to put out at this time without some help from Mother Nature.

“We are confident that most of it is under control, but it will continue to burn for days,” he said. “You know, we’re not going to put out the fire. Our goal is just to contain it, and we’re pretty confident we’re moving in the right direction. So smoke will remain in the area for quite some time until we get some good rainfall. That’s what we need.”

Wildfires have also been reported in other New England states in recent days. Dry conditions contributed to dozens of fires in Maine this weekend, including a large one in Buckfield that covered five acres. And in Rhode Island, firefighters responded to a brush and boat fire in Johnston on Monday morning.

Why do I smell smoke in Greater Boston?

Clearly, the smoke from these fires is affecting many of us.

All over the Boston area you can actually smell the smoke from those fires because of a weather phenomenon called inversion. That’s when warm air traps cool air and smoke close to the ground, and that can be a problem for air quality because smoke from wildfires has been shown to carry pollutants.

“Why you might want to be even more careful on days when smoke is present is because of that added toxicity,” says Jennifer Stowell of the Boston University School of Public Health. “The biggest concern is for people who already have underlying conditions.”

She said this may mean limiting outdoor activities if you have a respiratory condition such as asthma, and at the very least staying aware of air quality conditions.

Due to the wind direction in Middleton and North Reading, the air quality index in the area is between 52 and 56, according to the AirNow Fire and Smoke Map, meaning people sensitive to smoke should limit exposure.

But the fire burning in Salem, Lynn and Peabody is a different story. There, the air quality is considered unhealthy, ranging between 130 and 189. That means everyone should take precautions by reducing outdoor activities.

In Salem, public schools are suspending outdoor activities, with recess, physical education, outdoor education and sports remaining indoors until further notice.

And in Saugus, which is downwind of both fires, air quality is considered very unhealthy at 220 degrees, where everyone is recommended to limit or avoid outdoor physical activities.

“Air pollution in general can have both immediate and long-term effects, depending on the amount and intensity of exposure,” said Dr. Wynne Armand, an internist at Mass General Brigham. “Also, some of the immediate effects may be on the milder side. If there is irritation of the throat or eyes, or even a worsening of skin conditions such as eczema, more serious symptoms may include difficulty breathing, coughing, pain in the chest and palpitations.”

Health experts say people with underlying health conditions, the very young and the very old, should take extra precautions.