STONINGTON, Conn. (WTNH) — As soon as you head outside Tuesday, you want to head right back inside because it is so cold out.

The frigid temperatures led to some of the COVID-19 testing sites closing for the day, including the biggest one in the Stonington area at Dodd Stadium. The testing sites at the municipal building in the city of Groton on Tuesday and the Crystal Mall in Waterford on Wednesday will also be closed.

Some people who cannot avoid having to come out in the cold, like postal carriers and firefighters, are rotated out during calls outside in this cold so they can get warm while they work.

“Extreme cold and extreme heat are both enemies of the fire service,” said Old Mystic Fire Chief Ken Richards.

The hoses freeze up and so do the ground and the firefighters’ gear when water hits them.

The most common calls fire departments get when temperatures drop are for carbon monoxide concerns and no heat in homes. When things start to warm up and thaw out, they get calls for pipes bursting.

“When it freezes, it expands the pipe out, but it normally keeps the water in because the ice is there,” Richards said. “Then when it starts thawing out, the ice starts melting, and it gets moved on in the line, and then you got the crack in the pipe from it expanding from the ice.”

One thing you can do to prevent having to make an emergency call for a burst pipe is to make sure your pipes are insulated, especially if they are in a basement, a crawl space, or along an outside wall.

You should also drain and shut off outside faucets and insulate them. You can let an indoor faucet drip a little to keep the water moving so it doesn’t freeze up inside a pipe.