Dozens of wildfires continue to occur across the north coast of Massachusetts and the rest of the state. Firefighters are returning to the area on Tuesday to try to put out the flames.

The fire chief said more than 250 acres of land here in Middleton burned yesterday in a wildfire that spread to North Reading.

On Tuesday morning, smoke could be seen over Middleton Pond as several locations in the forest were still actively burning.

But for now, these flames are not threatening any homes in the area.

Hundreds of acres are burning in Massachusetts

Firefighters were driving around monitoring the fires Tuesday morning. As soon as the sun rises and visibility improves, they will again actively participate in combating hotspots.

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

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

And firefighters in Salem, Lynn and Peabody will continue to battle a more than 130-acre wildfire that has spread through those communities.

Middleton Fire Chief Douglas LeColst said these fires are too large to be extinguished at this time without the help of Mother Nature.

“We’re confident most of it is under control, but it will 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 sure we’re heading in the right direction. So there will be smoke in the area for a long time until it rains properly. This is what we need.”

Bushfires have also been reported in other New England states in recent days. The dry conditions contributed to dozens of fires in Maine over the weekend, including a large one in Buckfield that spread over five acres. And in Rhode Island, firefighters responded to a brush and boat fire in Johnston Monday morning.

Why do I smell smoke in the Boston area?

Clearly the smoke from these fires affects many of us.

All over the Boston area, you can actually smell the smoke from these fires due to a weather phenomenon called inversion. Then warm air traps cool air and smoke near the ground, and that can be a problem for air quality since wildfire smoke has been shown to carry pollutants.

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

She said that might mean limiting your outdoor activities if you have a respiratory illness like asthma, and at least keeping an eye on air quality.

Due to 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, classifying it as moderate, meaning people sensitive to smoke should limit exposure.

But the fire burning in Salem, Lynn and Peabody is a different story. The air quality there is considered unhealthy and is between 130 and 189. This means that everyone should take precautions and reduce outdoor activities.

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

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

“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. “Some of the immediate effects could also be milder.” Such as irritation of the throat or eyes or even an exacerbation of skin conditions such as eczema, more serious symptoms may include difficulty breathing, cough, chest pain and heart palpitations.”

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