The heat wave that has descended on Greater Boston intensified Friday, bringing dangerously high temperatures to the city.
The National Weather Service said Boston tied a heat record for July 22 with a 4 p.m. reading of 103 degrees at Logan International Airport. The heat index, which takes humidity into account, was well over 100.
An excessive heat warning remains in effect until Friday night for most of eastern Massachusetts as several other communities in the region also topped 100 degrees.
Public officials asked people to take care of themselves and watch out for others, and hospital emergency rooms were on heightened alert Friday. Local hospitals reported few heat-related issues through Friday afternoon.
"You can never be sure what's gonna happen but we're prepared and ready for anything that may come into the E.R," said Boston Medical Center's Gina DeGrazio.
Managers of the regional power grid were also closely monitoring the demand for power. Domenic Slowey, of power grid manager ISO New England, said it appears the region has just enough energy to meet the expected demand.
"We're watching the situation very, very closely for any changes, any breakdowns of transmission lines or any breakdowns of power plants that could change the outlook," Slowey said.
Jordan Hospital in Plymouth used an auxiliary air conditioning unit in an effort to cool off the building after two of its air conditioning units broke. The hospital canceled all surgeries scheduled for Friday, but the emergency room remained in operation.
To combat the heat, several cities have opened cooling centers and Boston's pools will remain open late, until 9 p.m., Friday.
Jane Bickford, a librarian in Jamaica Plain, says libraries are one place to beat the heat.
"Well I think a library is a great place, because they're all air-conditioned, and in the summer, there's usually a lot of activities going on," Bickford said.
Friday was the second straight day of a 100-plus heat index. NWS meteorologist Rebecca Gould said the heat index soared to 105 degrees in Boston Thursday.
Temperatures are expected to cool Sunday.
-- Scroll to the bottom of this post for Boston's cooling centers.
This program aired on July 22, 2011. The audio for this program is not available.