At just past noon, Christina Andrade and Belinda Cardoso got ready to leave Carson Beach in South Boston. The 20-year-olds had been at the beach since early Friday morning, but now, donning towels and drying their hair, they couldn’t take it anymore.
“It’s getting too, too hot,” Andrade said.
Not for everyone.
The beach was brimming with activity. Dozens ordered iced drinks, sunbathed, and swam, even as the temperature along the Massachusetts coast, including in Boston, skyrocketed past 90 degrees for the third day in a row — officially marking the season’s second heat wave.
The torpor-inducing temperatures, expected to last through Sunday, will feel hotter than the last, said Bill Simpson, a National Weather Service meteorologist. Friday’s high was 95 degrees with 55 percent humidity, he said, but the heat index, which combines temperature and relative humidity to measure how hot it feels, hit nearly 100. There will be no relief until Monday, he said, when temperatures should cool to the mid- to low-80s.
The hottest July 5 on record was in 1919, at 101 degrees.
In Boston, Mayor Thomas M. Menino issued a heat advisory through the weekend, urging residents to stay hydrated and in the shade or air conditioning. The city’s elderly commission made robocalls to 30,000 seniors warning them of the heat and providing the number of the mayor’s 24-hour hotline. The Boston Housing Authority activated cooling centers at all of its properties for the elderly and disabled.
By Friday afternoon, all Boston Centers for Youth & Families — 35 facilities, including community centers and pools — were turned into cooling centers with air conditioning and water available.
The mayor’s office also encouraged people to take advantage of water sprays around the city, which operate through mid-September.
Children and the elderly are particularly vulnerable to heat-related illnesses, but precautions can be taken, including limiting strenuous activity, wearing sunscreen and light clothing, and drinking plenty of fluids without caffeine or alcohol. If untreated, heat exhaustion or heat stroke can be fatal.
To respond to heat-related calls as quickly as possible, the city’s Emergency Medical Service put two extra trucks on duty Friday, said Nick Martin, spokesman for the Boston Public Health Commission. On a typical summer day, EMS receives 340 calls, he said, but by Friday afternoon, 200 calls had already arrived. Most were likely heat-related, he said.
“The biggest issues we see are heat exhaustion and dehydration,” he said. “But even conditions that don’t seem immediately heat-related, like asthma or heart conditions, can be exacerbated by heat.”
To stave off the heat, many turned to ice. The number of convenience stores and restaurants needing extra ice rose “exponentially” since the beginning of the heat wave, said Charlotte Ploss, sales manager at Brookline Ice & Coal, which specializes in ice delivery. The phones there rang nonstop Friday morning and afternoon, sometimes with customers requesting ice for the second or third time of the day.
One supermarket ordered 4 tons of ice, Ploss said. A restaurant called for so many ice refills that Brookline Ice & Coal offered use of a company trailer, which holds 3,000 pounds of ice. Because the restaurant does not have enough space for the trailer, its owner is parking it in his driveway, she said.
Back at Carson Beach, 54-year-old Ricky Maddock filled his water bottle from a beach shower spigot.
“I love the heat,” he said. “I just think of all those feet of snow we had this winter, and I can put up with this. The body always adjusts.”
At the water’s edge, Mike Carchen, 45, played with his 5-year-old grandson, Alejandro. They like the air conditioning, he said, but prefer to cool off in the ocean.
Seaside Cafe, which serves food and iced drinks to beachgoers, served a limited menu Friday in anticipation of growing crowds, said Holly Millette, a cashier. The limited menu also allowed staff to minimize use of heat-generating equipment, like stoves. Throughout the day, the cafe gave cups of ice to customers.
Across the street, at a local park, a group of kids played basketball. It was nearing the mid-90s. Kevin Charlot stopped for a water break and wiped his brow.
“It’s really hot to play,” the 14-year-old said. “But I love the game.”
Nikita Lalwani can be reached at nikitalalwani @globe.com.