Maryland health officials have activated a state heat emergency plan, and some counties have followed suit, with temperatures already topping 90 degrees by 11 a.m. Wednesday.

The state Department of Health and Mental Hygiene is warning residents to be wary of heat-related illnesses like heat stroke and heat exhaustion. Heat stroke symptoms include dry red skin, convulsions, disorientation, delirium and coma. Heat exhaustion is a milder form of heat stroke and can cause extreme weakness, muscle cramps, nausea, or headache.

There were 34 heat-related deaths in Maryland last year, according to the state health department.

Temperatures reached 97 degrees, with a heat index of 100, by 3 p.m. at BWI Marshall Airport. Downtown at the Sun weather station, the temperature was 97 and heat index 112 as of 3 p.m. Earlier in the afternoon, the temperature on Centre Street hit 98 and the heat index 115, some time between 1:30 p.m. and 2 p.m.

Baltimore City opened its cooling centers at 9 a.m. and activated a Code Red heat emergency. More information on cooling resources available in the city can be found here.

Anne Arundel County opened ten cooling centers, four of them open 24 hours a day during the heat emergency. County residents can call 410-222-0600 for information on the centers and other cooling resources.

Carroll County has opened cooling centers at each of its public library branches as well as its Citizen Services Office Building, Mount Airy Senior and Community Center, North Carroll Senior and Community Center, South Carroll Senior and Community Center, Taneytown Senior and Community Center and Westminster Senior and Community Center.

Howard County officials are encouraging those who need to cool down to visit its senior centers and public libraries.

The National Weather Service's heat advisory for all of central Maryland went into effect at noon, and officials extended it to 10 p.m.

To cope with the heat, the weather service encourages residents to:

  • Drink plenty of fluids,
  • Stay in air-conditioned rooms if possible,
  • Stay out of the sun,
  • Check on neighbors and relatives,
  • Reschedule strenuous activities to early morning or late evening,
  • Wear light-colored, loose-fitting clothing, and,
  • During outdoor work, take frequent rest breaks in air conditioning or under shade.