The high in Chicago today was -12 degrees Fahrenheit and at its worst, wind chills in the morning made it feel like nearly -50 degrees outside. The once-in-a-generation, dangerous polar vortex prevented glaziers across the Midwest from working outside in unsafe conditions.

“We have shut down all activities that are outside [today]. Typically, we work until zero degrees but it becomes challenging because A) the guys need to continually warm up which loses a lot of productivity and B) the batteries don’t last due to it being so cold,” says Eric Martinson, president of Northern Glass Inc. in Elk Grove, Ill. “We are only working one job [today] (it’s inside) due to certain circumstances. Our glass supplier for that project will not deliver glass [today], so we sent multiple flatbed trucks up to their facility [yesterday] so that we can work that job [today].”

Northern Glass isn’t the only company opting to work inside today. According to Patrick Hill, president of of Illinois in Elmhurst, Ill., his company opted to assist with two emergency calls.

“We got a call from a Starbucks in downtown Chicago that wanted someone there today,” says Hill.

Two of the four guys who came to the shop today went out to fix a door problem. He says they will work from the inside of the Starbucks and if they need to go outside, only will do so for less than four minutes at a time.

“You can’t even go outside, it’s miserable here. It’s really bad. As soon as you go outside that breathe of air just hits you. My small dog wouldn’t even go outside this morning,” says Hill.

Traditionally, Glass Designers Inc. in Chicago defers to inside jobs when the temperature falls below zero degrees. However, operations manager Brian Anderson says it’s so dangerously cold that the company can’t do inside jobs today since there’s only a temporary enclosure available at these jobsites.

“We’re staying out of the cold until it’s above zero degrees,” he says. “The frigid cold is shutting everything down.”

Anderson adds he surprised that deliveries were coming in today with the temperature so low.

Several companies have closed completely today and plan to reopen tomorrow.

“Due to the dangerously cold weather, Alside will be closing both the Rogers and Bloomington locations on Wednesday 1/30. We are planning on returning to normal business hours Thursday morning,” reads an out of office email from Alside Exterior Building Products’ supply center near Minneapolis.

“Due to the extreme weather our office will be closed today Wednesday, January 30th and re-open tomorrow Thursday, January 31st,” reads another out-of-office message from FitzGerald Associates in Chicago.

Another from Triumph Engineering LLC in Appleton, Wis., reads, “Our offices will be closed today, Wednesday January 30th due to extreme winter weather. We will be available first thing tomorrow morning and will get back to you as quickly as we’re able.”

The weather in Chicago tomorrow is expected to be a high of 2 degrees and a low of zero degrees, which means that many glaziers and glass shops will be back in the field. Temperatures in Minneapolis and Milwaukee are expected to hover just below the zero-degree mark tomorrow, but rise to the twenties and teens by Friday.