For example, the $939 million FORUM Credit Union in Fishers, Ind., where the Monday afternoon temperature plummeted to minus 10 degrees below zero with a wind chill of minus 31, the cooperative apologized to members for closing the branches but explained that the safety of its employees and members is important, according to a FORUM CU Facebook post.

Nonetheless, FORUM member Myna Pettit Allison Dowden wrote: “Thank you for thinking of your people. That, above all, is what is most important. Even more important than money.”

More than 30 people “liked” Dowden's comment.

FORUM CU announced Tuesday morning that is would be opening its branches but not until 10 a.m.

Also shutting down its branches was the $416 million Vibe Credit Union in Novi, Mich., where Monday temps plunged to 5 below zero with a wind chill of minus 31.

“Thank you Vibe!” wrote member Dawn Stieve Jozefowicz on credit union's Facebook page. “Setting a great example by keeping employees safe.”

The Arctic's bitter cold blast even reached the deep southern states that forced the $1.3 billion Associated Credit Union in Norcross, Ga., to close their branches early at 4:30 p.m. The temperature at noon in Atlanta was only 17 on Monday, about 35 degrees lower than the average January high of 52, according to the Weather Channel.

Because of the subnormal temps, the credit union said its branches would not open until 10 a.m. Tuesday. They normally open at 8 a.m.

Credit Union Association of New York Communications Director Mindi Schwab said many member credit unions in the Buffalo/Niagara region were closed Tuesday due to severe weather. On Facebook alone, CUANY found closed branch notices messages from eight credit unions that have locations in the area, she said.

Read more: Wisconsin credit union mocks subzero temps …

Other credit unions were open in areas in the Polar Vortex, like the $2.3 billion Landmark Credit Union in New Berlin, Wis., which open on Monday and offered winter safety tips for members on its Facebook site. The $14.6 million South West Communities Credit Union in Carnegie, Pa., passed on information to members that a local police station was opening as a “warm center” for anyone who lost power in their homes.

The $1.3 billion Royal Credit Union in Eau Claire, Wis., also had its branches operating in Wisconsin and Minnesota despite both states recording some of the lowest temperatures in the nation Monday.

Because folks in Wisconsin and Minnesota are used to very cold weather, Royal CU took the opportunity to post a humorous “Wisconsin Poem” on its Facebook site:

It's Winter in Wisconsin

And the gentle breezes blow.

Seventy miles an hour,

At thirty-five below.

Oh, how I love Wisconsin,

When the snow's up to our butt.

You take a breath of winter air

And your nose gets frozen shut.

Yes, the weather here is wonderful

So I guess I'll hang around

I could never leave Wisconsin,

'Cause I'm frozen to the ground!

The temperature in Eau Claire Tuesday morning was 19 below zero with a wind chill of 36 below zero, according to the Weather Channel.