Baltimore City is under a code blue extreme cold alert until Tuesday morning.

It's the fourth code blue declaration this season. Baltimore City officials are urging residents to stay inside.

The Maryland Office of the Chief Medical Examiner has reported three cold-weather-related deaths this season.

A code blue extreme cold alert can be declared when temperatures, including wind chill, are expected to be 13 degrees or below, or when other conditions are severe enough to present a substantial threat to the life or health of city residents.

During a code blue, the city's response partners work to ensure those in need find shelter.

For those who have to be outside, officials suggest dressing in layers, wearing a hat and scarf and drinking plenty of fluids.

"The weather today is out of control. It is cold out here. You need to go in the house, wrap up, gloves, you know what I mean, hats and everything. Nobody needs to be out here. This is pneumonia weather," said Rashaad Smith, of Baltimore.

"It's the wind, it's the wind. It's not even the temperature. The temperature is not that cold. It's just the wind that is horrible," said Hannah Guan, of Baltimore.

During the code blue season, city officials work with homeless shelter providers to extend their hours and provide expanded bed capacity.