The National Weather Service has issued several heat-related advisories for the New London area.

An excessive heat warning is in effect for northern New London County until early tomorrow morning. A heat advisory is in effect for southern New London County.

A heat advisory goes into effect when it's expected that humidity and high temperatures will combine to make it feel like it's between 100 and 104 degrees for two hours in a row. An excessive heat warning means it will feel like it's 105 degrees or more.

The weather service has also issued an air quality alert that will remain in effect until tomorrow afternoon for northern and southern New London County.

On Friday, temperatures in the New London area will reach 93 degrees, but it will feel like it's 100 degrees, the weather service said.

It will feel worse in the Norwich area with the high near 96, but with heat index values it will feel as high as 103 degrees.

Cooling shelters have already opened in response to the heat. The following shelters are open:

Griswold -- The Senior Center at 22 Soule St., Jewett City, will act as a cooling center today and Friday. The center is open from 8 a.m. to 7 p.m.

New London -- The city will open a cooling shelter today and Friday, 8:30 a.m. to 5 p.m., at the New London Senior Citizens Center at the Richard R. Martin Center, 120 Broad St., New London.

Old Lyme -- The Lymes' Senior Center will be open as a cooling center today and Friday. The senior center is located at 26 Town Woods Road in Old Lyme. For more information, contact the center at (860) 434-4127.

Norwich – The city emergency management department has designated the Rose City Senior Center as a cooling center. The senior center at 8 Mahan Drive normally is open Monday to Friday, 8 a.m. to 4 p.m., but hours might be extended into the evenings on those days and on Saturday if necessary.

Salem - The Salem Library will act as a cooling center on Thursday and Friday. It will be open Thursday from 10 a.m. to 7:30 p.m. and on Friday from 10 a.m. to 6 p.m. The library is located at 264 Hartford Road.

The Ledyard Fire Company and Gales Ferry Volunteer Fire Company have opened as cooling centers for residents looking for a place to beat the heat.

Ledyard Fire Chief Steven Daggett said this afternoon that the department opened around noon and will offer water to residents.

"It's absolutely brutal outside, if any residents are uncomfortable, they can come cool off here," Daggett said.

He said residents are welcome to spend the night at the fire department, but they will need to bring a sleeping bag, pillows and blankets as the sleeping bunks are for firefighters only. The department does not have any cots.

The Gales Ferry Fire Department will also allow residents to spend the night, but advised that they bring a sleeping bag, pillows and blankets, as cots are limited.

The Ledyard and Gales Ferry departments are open for the next 72 hours, as a heat wave moves over the region.

The Ledyard Fire Company is located on 11 Fairway Drive. They can be reached at (860) 464-9222

The Gales Ferry Volunteer Fire Company is located on 1772 Route 12. They can be reached at (860) 464-7228.