Mystic — After almost 50 years of running alongside hundreds of participants before splashing into Fishers Island Sound on New Year's Day, Amby Burfoot says he's not so sure about the splashing part of the equation this year.

"I'm getting a little bit old for that kind of frigid plunge," Burfoot said with a chuckle Friday, citing forecasts of bitter cold beyond almost anything participants in the popular-but-unnamed-and-unaffiliated annual run-swim have experienced since 1969. "The vast majority of years have been between 30 and 50 degrees."

But arctic air sweeping through the region this weekend — trapped by a ridge of high pressure near Greenland — will drag Monday morning temperatures down near 0 degrees, according to Gary Lessor, a meteorologist and assistant director with The Weather Center at Western Connecticut State University in Danbury.

"We still don't see any signs of normal conditions in the next week," Lessor said, noting Monday's temperature may hit the mid-teens by the afternoon, compared to typical average highs of 39 degrees and lows of 25 degrees this time of year. "It looks like we stay in the 20s most of next week. We may pop into the low-30s on Wednesday."

Burfoot, the 71-year-old 1968 Boston Marathon winner, noted he still expected a large turnout to gather at noon Monday at the Johnny Kelley statue in Mystic for the 3.5-mile run-swim. He believes "a hearty handful will go into the waters" regardless of reports of bone-chilling conditions that have inspired some organized plunges to cancel.

"I do recall thinking I'd die between the water and the car waiting for me (in the inaugural 1969 run, when it was 18 degrees)," Burfoot said. "But we survived. I'm sure those who plunge this year will also survive. Runners are very adept at dressing for the cold ... and the run warms us up after five or 10 minutes."

This week's icy arctic air shattered a host of low temperature records from the Midwest to New England, with Lessor saying "basically the entire eastern half of the country has seen all the cold air settle here."

On Friday, Nathan Hale Arts Magnet School announced on its website it would be closed on Tuesday due to “burst pipes and damage from the freezing temperatures.” The plan is for school to resume at a normal start time on Wednesday.

And heating problems in the New London High School gym forced officials to postpone a 4 p.m. Friday boys' basketball game against New Britain until Saturday, Jan. 6, at 4 p.m, according to coach Craig Parker.

"We practiced in the gym (Thursday) and it was definitely cold in there," he said, noting crews would try to fix the heating issue to ready the gym for a 1 p.m. matchup Saturday against Hartford Public. "It's not easy to reschedule games. It has to work out with the two teams and families."

If the heating problem isn't resolved soon, it would leave the team "scrambling for a facility in New London to practice," Parker said. He noted the team potentially could host games at Bennie Dover Jackson Middle School, if necessary.

While Lessor said southeastern Connecticut hasn't seen new low temperature records, Thursday broke records in Bridgeport, Groton and Bradley International Airport for "coldest high temperatures ever" at 18, 15 and 11 degrees, respectively.

On Thursday, the Associated Press reported that weather observers atop Mount Washington, the northeast's highest peak, said temperatures dropped to negative 34 degrees, three degrees colder than the previous record, which was set in 1933.

Even as weekend temperatures rise to the mid-20s, Lessor encouraged locals to bundle up and brace for a biting wind chill that will make it feel like the air's in the mid-teens. They also should keep snow shovels at the ready.

"It's a light snow or snow shower early in the afternoon or evening (Saturday)," said Lessor, who forecast up to 2 or 3 inches of snowfall in some locations.

On Friday along Long Pond Road South in Ledyard, a Lucas Tree Experts crew kept warm by busily trimming hazard trees before any potential snowstorm.

"We trim along power lines and prevent damage," Lucas Tree Experts' Dan Humbert said, noting the company was contracted by Eversource. "We try to get ahead of it and get it all down so it creates less of a problem in the future. We try to make the customers happy as much as possible, so we're not just going out and hacking people's trees. But you have to think about everybody on the roads, too."

The crew donated woodchips to the organic Earth Friendly Farms down the road, much to the delight of farm owner Kirk Bryson, who let the crew cut a few trees on his property earlier this year.

"Five days ago before the cold hit, everything was turning to mud," said Bryson, who raises pigs, sheep, goats and chickens. "So we'll do all of our paths with the woodchips, insulate around some of the buildings so wind can't get underneath, and then the chips are mixed with manure and after about a year we can throw it in the garden."

b.kail@theday.com