For many states, winter and cold weather go hand in hand. We’re used to shoveling snow from our driveways, and we’ve learned some helpful tricks to keep ice off of our cars; however, this year is different.

If you live in certain northern states, you may be hunkering down inside your home with the heater running at full blast. It’s not snow or ice that’s the issue, it’s below zero temperatures that are made even worse by wind chill. We’re talking -60. That’s cold enough that even a few minutes of exposure could cause frostbite or hypothermia.

Don’t bother braving the cold conditions to check your mail today, because if it’s that cold where you live, chances are your postal carrier is not going to be delivering any mail.

The post office has a motto that pretty much means they’ll deliver mail in all conditions. “Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds.”

While that motto mentions heat, it doesn’t say anything about cold weather. Looks like extreme cold might be the one exception to completing their “appointed rounds.”

Imagine being a mail carrier. Many mail carriers walk from mailbox to mailbox delivering letters, bills and junk mail. If even a few minutes of exposure to these extreme cold temperatures can be dangerous, mail carriers might be risking their lives and their limbs if they went to work as usual. Thankfully, the postal service sees the danger.

According to the United States Postal Service’s announcement, “Due to this arctic outbreak and concerns for the safety of USPS employees, the Postal Service is suspending delivery Jan. 30.”

The following states are affected by the temporary mail delivery suspension: Michigan, Indiana, Illinois, Ohio, Nebraska, North Dakota, South Dakota, Minnesota, Wisconsin, Iowa, and Pennsylvania.

Mail delivery is only suspended in certain zip codes of these states. If you live in one of these states, and if you would like to see if your area is affected, you can view updates from USPS here.

For more information about how the polar vortex is affecting mail delivery service, watch the video below.

What’s the weather like where you live? Is the polar vortex affecting your state?