Sunday will be hot and downright unpleasant, a day after Saturday’s high temperatures led people to seek sanctuary from heavy, humid air at public beaches and inside movie theaters.
Boston EMS and electrical utility Eversource had additional crews working over the weekend in case of problems due to the weather. Emergency crews and hospitals, however, reported only a few medical issues related to the heat.
“Humans often feel so strong, but such a thing like weather can quite humble us,” said Donna Hakimian, who was inside the air-conditioned lobby at the AMC Boston Common 19 movie theater Saturday afternoon. “We’re fragile.”
And be prepared to be humbled again, as Greater Boston is expected to have scorching temperatures in the upper 90s to potentially 100 degrees Sunday.
And the heat index, a measure of how temperatures feel when humidity is added to the mix, is expected to reach 100 to 110 degrees, said Bryce Williams, a meteorologist with the National Weather Service in Norton.
It’s possible, though not likely, that Boston could match its record for heat Sunday -- 102 degrees, set in 1977, he said.
He hopes it will not: “I’d rather be outside and not melt,” Williams said.
The weather is expected to take a turn for the better then as a cold front moves through Sunday night, he said, bringing with it a small chance of rain, followed by temperatures in the low- to mid-80s Monday and more rain. Forecasters are expecting heavy downpours Monday night and into early Tuesday, he said.
Tuesday also brings “real relief,” he said, and temperatures in the low 70s. The remainder of the week is expected to have temperatures in the 80s with little or no rain, he said.
Sunday follows an oppressive Saturday night, with temperatures no lower than 81 degrees overnight, he said.
“It’s very impressive, and not in a good way,” Williams said.
During the day Saturday, temperatures in Boston climbed to a high of 97 degrees, a few degrees shy of the record of 99 set in 1991, Williams said. Saturday morning’s low of 80 degrees matched a previous record set in 1977, he said.
The excessive heat can cause breathing problems and heat cramps, and lead to serious conditions, including heat stroke and illness, the Massachusetts Emergency Management Agency said in a statement.
The extreme heat also means air conditioners and fans are working overtime.
In Sandwich, a Saturday morning power outage due to equipment failure interrupted service to about 1,200 customers for two hours, said Reid Lamberty, a spokesman for Eversource, although it wasn’t clear if that was related to the hot weather.
“We do have crews ready to respond to any issues or any outages that may arise,” he said.
Boston Emergency Medical Services had 12 transports to local hospitals directly attributed to heat-related illnesses over Friday and Saturday, according to Erin Serino, the agency’s deputy chief of staff.
Beth Israel Deaconess Medical Center, had seven patients in its Emergency Department by Saturday afternoon with heat related complaints, said Jennifer Kritz, a spokeswoman.
At Massachusetts General Hospital, one patient sought care due to the heat as of 5 p.m, said spokeswoman Katie Marquedant.
Barbara Trevisan, a spokeswoman for Pine Street Inn, said the organization had stepped up its outreach services to check on people in the street, and bring them cold water, sunscreen, and bug spray.
“Most of all, they are urging people to come inside to our air-conditioned shelters, which have been open around the clock,” Trevisan said.
If anyone sees someone in distress on the street, Trevisan said to call 911.
Bay State residents looking for a cooling center this weekend should check with local authorities or call 211 for information, MEMA said in a statement posted to its website.
In Boston Thursday, Mayor Martin J. Walsh declared a heat emergency from Friday through Sunday, and the city has opened additional community centers this weekend to serve as places where people can cool off. A list of centers is available on the city website.
Ashley Manning, who sat in a chair on the beach at the BCYF Curley Community Center in South Boston Saturday afternoon, said the ocean was “a little cold, but refreshing.”
“This beach is the best thing that’s ever happened,” she said. “It’s perfect.”
The extreme heat also led the Braintree Police Department to make an unusual request to criminals: Hold off on committing crime until Monday.
“Conducting criminal activity, in this extreme heat is next level henchmen status, and also very dangerous,” police said in a Facebook post Saturday. “Stay home, blast the AC, binge Stranger Things season 3, play with the face app, practice karate in your basement[.] We will all meet again on Monday when it’s cooler.”
Some took advantage of the summer movie blockbuster season to beat the heat at the AMC Boston Common 19.
Srikar Yellapragada, of Cambridge, who was visibly drenched in sweat as he entered the theater on Tremont Street, said the blistering heat reminded him of the unforgiving climate in southern India, his home country.
“My place doesn’t have AC, so I thought this could be a good way to escape the heat,” he said.
Katie Muldoon, said she and her friends had quickly planned to go see a movie after hearing Saturday’s forecast.
Muldoon shivered in the AMC lobby as she gestured to her tank top.
“I always know it’s going to be freezing in the theater, but I couldn’t bring myself to wear a sweater,” she said. “It’ll touch my arm and then my arm will fall off.”Globe correspondent Lucas Phillips contributed to this report. John Hilliard can be reached at email@example.com. Alison Kuznitz can be reached at firstname.lastname@example.org.