Dry weather fuels brush fires statewide

In addition, battling the blazes has proved to be more difficult as firefighters balance the weight of their gear with the searing heat of both the fires and the air outside.

“I’ve had better days,’’ an exhausted Stephen D. Coan, the state’s fire marshal, said Tuesday.

Brush fires have been reported from Cape Cod to the Merrimack Valley to Western Massachusetts. Serious brush fires have broken out in Mashpee, Dennis, Tyngsborough, Groton, Holden, Canton, Medford, Plymouth, and Franklin.

“The weather conditions are very favorable for the type of fires we are seeing,’’ Coan said. “I would expect that we will see a continuation of fire throughout the state until we see some appreciative precipitation.’’

One of the most intense brush fires has been in Holden, where Fire Chief Jack Chandler said the blaze spread across 25 to 50 acres and crews will go back to the scene this morning to extinguish up to 100 hot spots.

All told, 29 cities and towns have provided assistance, the Holden Fire Department said in a statement. Four firefighters suffering from heat exhaustion have been taken to the hospital, the statement said. They have all been released.

Chandler said the area is a popular spot for youths, and he suspects a camp fire might be to blame.

The Holden fire was just one of the serious brush fires reported since July 1. Often, the fires have been in remote areas. But they have also often been far from roads and farther from fire hydrants, making it difficult for firefighters to mount an attack.

Yesterday, crews in Groton were battling the second brush fire to hit the town this week. The blaze spread across 6 to 8 acres and crews were still fighting it yesterday, Coan said.

A concert and fireworks display originally scheduled for Tuesday in the town was postponed because of concern over extreme weather conditions, according to the town’s website. A fire dispatcher said yesterday that the event has not been rescheduled.

Crews have spent at least two to three days fighting some of the blazes, according to Dave Celino, chief fire warden for a division of the state Department of Conservation and Recreation, which handles forest fires.

He said a National Guard helicopter with the capacity to drop 600 gallons of water onto affected areas is on standby but has not been deployed, because houses have not been threatened. But, he added, a State Police helicopter has flown over several of the fires to inform crews about smoke conditions and other hazards.

Coan said many firefighters have been treated at the scene for dehydration and heat exhaustion. He said he was not aware of any firefighters besides the four in Holden being taken to the hospital.

“The drink of the day is water,’’ Coan said. “These are very difficult conditions. In structure fires and wildfires, the conditions are extremely dangerous for firefighters and require special consideration to ensure safety.’’

Coan has circulated guidelines to fire departments underscoring the importance of hydration and rotating crews in and out of fire scenes to rest.

The usual guidelines for the public apply to preventing brush fires: carefully dispose of cigarettes and other smoking materials and do not light a campfire or other outdoor cooking fire without a permit from the local fire department, Coan said.

Globe correspondent Vivian Ho contributed to this report. John M. Guilfoil can be reached at jguilfoil@globe.com, and Travis Andersen can be reached at tandersen@globe.com.