BOSTON -- With temperatures topping 90 degrees for the third day in a row, Boston Mayor Thomas M. Menino ordered city pools to be open on Sunday. Pools are normally closed.

The extended pool hours for Sunday, July 18 were 12-8 p.m.

In addition to issuing a heat advisory, Menino was also urging residents to utilize the city's cooling centers which were open across the city.

Both children and adults took advantage of the extended Sunday hours, as pools and centers were packed.

Parents at the Clougherty Pool in Charlestown and the Mirabella Pool in the North End were happy they had places to take their kids to cool off.

“It’s working out great,” said parent Toya Joseph. “The kids can be in here and have fun.”

There were no complaints from the kids.

“I’m really happy because it’s an awesome pool,” said one little girl. “And you get to find your friends.”

During extremely hot weather, children and the elderly are particularly vulnerable to heat-related illnesses and injuries. But city officials were reminding everyone to limit their activities, drink plenty of fluids and avoid beverages that contain caffeine or alcohol.

When outdoors, people should also wear sunscreen and loose, light-colored clothing and rest often in cool, shady areas. Additional measures to beat the heat include avoiding cooking, taking cool showers or baths and staying in air conditioned areas whenever possible.

Residents were being reminded that fire hydrants should not be tampered with or opened. Doing so could hinder fire prevention capabilities.

For questions about heat-related city services, residents should call the Mayor's 24-Hour Hotline at 617-635-4500. Comprehensive heat safety tips and resources were also available on the city website, www.cityofboston.gov/heat.

Boston Public Pools:

Clougherty Pool 151 Bunker Hill St, Charlestown

Curtis Hall Community Center 20 South Street, Jamaica Plain

Draper Pool 5279 Washington St., West Roxbury

Flaherty Pool 160 Florence Street, Roslindale

Mason Pool 176 Norfolk Ave, Roxbury

Mirabella Pool 475R Commercial St, North End

Paris Street Pool 113 Paris Street, East Boston