New Jersey is getting its first taste of winter this season, prompting some towns around the state to issue a cold-weather warning to its residents.

Some municipalities like Newark have issued a “Code Blue” due to the weather conditions. In Newark, an alert is issued when temperatures are expected to reach 25 degrees or lower without precipitation like rain or snow or 32 degrees or lower with the precipitation.

The alert allows the city to open its shelters to the homeless or others who may not have heat. It also allows health officials, with the support of police, to go out to pick people up to bring them to the shelters for their own safety.

“The next 48 hours is going to be pretty severe,” says Newark health director Dr. Mark Wade. “Frostbite can occur at any point and you don’t necessarily realize that you’ve been frostbitten.”

Forecasters say that overnight temperatures in Newark will get down to the low-20s. But wind chills may make conditions feel as if they are in the teens or single digits.

Health experts say that everyone should limit the amount of time spent outside Tuesday night. Warm clothing, including hats and gloves, should be worn outside at all times.

People are also being warned to be mindful of surfaces that may freeze overnight and of icy conditions.