National Weather Service (NWS) meteorologists are warning of hypothermia risks in six southern states as wind chill causes the feels-like temperature to hit subzero levels in some areas.

On Tuesday morning, a cold weather advisory was in place for New Mexico, Texas, Louisiana, Mississippi, Alabama, and the Florida panhandle. Other cold-weather related alerts, such as a freeze watch, were in place for Arizona, Louisiana, Georgia, and Florida.

Why It Matters

The advisories come as much of the central U.S. is recovering from a winter storm that dumped over a foot of snow in some areas. In addition to the frigid temperatures, some southern states are also expecting snow, and vulnerable people could be at risk of illness.

What to Know

Hypothermia occurs when someone’s body temperature dips below 95 degrees Fahrenheit. It is considered a medical emergency and can be fatal.

In low-elevation areas, wind chills were dropping temperatures into the mid-teens or low-20s. However, in higher-elevation areas, wind chills are expected to plunge the feels-like temperatures to subzero territory.

A cold weather advisory issued by the Odessa, Texas, NWS office warned of wind chill as low as 13 below zero for the Guadalupe Mountains above 7,000 feet. Feels-like temperatures could dip to minus 5 degrees in parts of south central and southwest New Mexico and southwest Texas.

The NWS office in El Paso, Texas, said temperatures are expected to be as much as 20 degrees below average levels.

Temperatures were so cold in the Mobile, Alabama, forecast region that meteorologists suggested that people “avoid outdoors activities if possible” and dress in layers.

Some of the cold weather advisories were set to expire Tuesday, including in parts of Mississippi and Louisiana. Others, however, are expected to go into effect overnight and remain in place until late Wednesday morning.

What People Are Saying

NWS meteorologist Zak Aronson told Newsweek: “It is pretty unusual to get this cold. Up in the mountains is maybe a little more common, but it is probably some of the coldest air we will see this winter.”

NWS office in New Orleans, Louisiana, in a cold weather advisory: “Very cold temperatures and wind chills can lead to hypothermia if proper clothing is not worn. Use caution while traveling outside. Wear appropriate clothing, a hat, and gloves.”

NWS office in El Paso, Texas, in a cold weather advisory: “Keep pets indoors as much as possible.”

NWS office in Albuquerque, New Mexico, in a cold weather advisory: “Make frequent checks on older family, friends, and neighbors. Ensure portable heaters are used correctly. Do not use generators or grills inside.”

What Happens Next

Temperatures will likely remain below average across much of the South through at least January 20, according to an eight- to 14-day temperature outlook from the NWS Climate Prediction Center. The highest chance at below-average temperatures in the South will occur in the six- to 10-day time frame, according to the outlook.