Baltimore City officials have declared a Code Red Extreme Heat Alert for Tuesday, when the heat index could reach 105 degrees.

The alert, which comes after a similar one weeks ago, signals dangerous conditions for people outdoors, and means the city will open cooling centers for people to escape the heat. The heat index is what the outside temperature “feels like” when you combine the temperature and relative humidity.

The National Weather Service issued a heat advisory from 1-7 p.m. for the region, including Baltimore, southern Baltimore County, Anne Arundel County and the Eastern Shore.

The NWS forecast bulletin says a heat index of 107 degrees is possible closer to the Chesapeake Bay.

“This is a time for all of us to take extra precautions – stay hydrated, limit outdoor exposure when possible, and check on others — especially older adults, children, those with preexisting health conditions and pets," interim health commissioner Mary Beth Haller said in a statement.

Heat is the deadliest form of extreme weather and killed at least 25 Marylanders last summer.

There have been 8eight heat-related deaths reported in Maryland so far this year, according to the latest available data from the Maryland Department of Health. One of them was in Baltimore.

For a list of cooling centers, refer to the city’s website.

This article may be updated.