Western Massachusetts residents grappled with the heat on Friday as temperatures hit the low 90s.
A heat warning issued by the National Weather Service continues through Saturday evening.
"Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors," the weather service said in its bulletin. "Young children and pets should never be left unattended in vehicles under any circumstances."
In Holyoke, Mike Goncalves was working on a water main for the city and doing some paving. He has to wear long pants for his job, but said the hot weather is nothing new for him.
"Year after year, you get used to it," he said. "You just got to tough it out. But drink a lot of water — that's the key. Just a lot of water."
It was a busy scene at the John. S. Thomas Memorial Swimming Pool in Springfield. Lisa Ramsey was there, but said she didn't mind the temperature.
"It's hot, but I enjoy the heat. I enjoy it," Ramsey said. "And I love to swim, so here I am."
Cities across the region, including Springfield and Holyoke, opened cooling centers. Residents can get information by calling the state's 2-1-1 non-emergency hotline.
Cooler weather is forecast to arrive Sunday, with western Massachusetts temperatures topping out in the low 80s.