Baltimore City's health commissioner has issued the city's first Code Blue extreme cold alert of the season.

Dr. Letitia Dzirasa, the city's health commissioner issued the warning effective from Wednesday evening to Thursday morning.

“With dangerously cold temperatures expected, I am issuing a Code Blue Extreme Cold declaration beginning Wednesday evening through Thursday morning. I encourage residents to stay indoors,” Dzirasa said in a statement. “Please be sure to check on neighbors who may be at risk to ensure they have heat and power, and take care to shelter pets.”

A Code Blue alert may be issued when temperatures, including wind chill, are expected to be 13 degrees or below or when other conditions combine to create a substantial threat to the life or health of vulnerable residents.

Last winter, the city had 13 Code Blue days. The Office of the Chief Medical Examiner recorded 13 cold-related deaths in the city.

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.

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