As a dangerous heat wave sweeps through Maine, with temperatures approaching triple digits, communities are advising vulnerable groups to seek shelter in cooling centers. These are air-conditioned buildings that are designated as a safe place to cool down during extreme heat events.

High temperatures and dew points culminate on Thursday, making it feel more difficult to regulate your body temperature.

According to the National Weather Service, the heat wave is expected to be the most significant since 2020 when Portland reached 93 degrees on June 20.

Coastal Maine will be the place to be, with temperatures slightly cooler than inland. Highs will still be in the high 80s to low 90s, but a sea breeze will offer slight relief. Nearing Brunswick/Topsham, temperatures rise 5 degrees with a heat index close to 100 degrees.

“There’s a high-pressure system passing through,” said NWS meteorologist Stephen Baron. “A strong southwesterly flow of hot air has entered the area, unimpeded. Luckily, a cold front will arrive on Friday, helping to alleviate things as we head into the weekend.”

Extreme heat and high humidity can increase the risk of heat illnesses like heat stroke. Drink plenty of fluids and stay in a cool, well-ventilated area, and avoid the sun when possible.

Baron warned a dip in the ocean to cool off could lead to hypothermia. Instead, Midcoast towns are offering public cooling centers to beat the heat.

The hours below will remain in effect through Thursday, June 20.

Brunswick

The Brunswick Parks and Recreation Department at 220 Neptune Dr. will be open from 6 a.m. to 8 p.m.. As will the Curtis Memorial Library at 23 Pleasant St. from 9:30 a.m. to 8 p.m.

Topsham

The Topsham Hearth Doctor Showroom at 11 Main St. will be open from 9 a.m. to 5 p.m. No food or refreshments will be offered, just air conditioning and some chairs to rest.

Harpswell

The Harpswell Town Office at 263 Mountain Road will open earlier than usual, from 11 a.m. to 6:30 p.m. While the Orr’s Island Library at 1699 Harpswell Islands Road is typically closed on Wednesdays and Thursdays, it will open from 10 a.m. to 5 p.m. during this hot stretch.

Phippsburg

The Phippsburg Town Hall at 1042 Main St. will be open from 9 a.m. to 5 p.m. As will the Fire Station at 1060 Main Road, which plans to remain open as long as needed.

Wiscasset

The Wiscasset Community Center at 242 Gardiner Road will be open from 5 a.m. to 8 p.m.

Boothbay

The Boothbay Harbor YMCA at 261 Townsend Ave. will be open from 5:30 a.m. to 8 p.m.

Richmond

The Richmond Senior Center at 314 Front St. will be open from 10 a.m. to 5 p.m.

Bridgton

The Bridgton Community Center at 15 Depot St. will be open from  9 a.m. to 5 p.m. The cooling center will also serve as a charging station. Note, that no pets are allowed.

Damariscotta

The Damariscotta YMCA at 525 Main St. will be open from 5 a.m. to 8 p.m.

Bowdoinham

The Bowdoinham Fire Hall at 57 Post Road will be open from noon to 8 p.m.

Woolwich EMA Director Chief Shaun Merrill is continuing to access the situation. If necessary the town office at 13 Nequasset Road will open as a cooling center from 8 a.m. to 4 p.m. Residents are encouraged to check the town website and Facebook for updates.

Georgetown plans to follow suit. Should temperatures exceed high 80s the town website and Facebook will notify locals on available shelters.

For a list of statewide cooling centers visit the Maine Emergency Agency site or call 211.