Howard County Under Heat Advisory on Tuesday

We aren't finished with dangerous heat yet, according to forecasters. A heat advisory has been issued from noon until 8 p.m. Tuesday for Howard County.

The heat index, or "feels like" temperatures, will reach up to 109 degrees Tuesday afternoon across the region, according to the National Weather Service, which said actual temps will be in the mid to upper 90s.

The heat advisory encompasses Anne Arundel, Baltimore, Calvert, Charles, Harford, Howard, Montgomery, Prince George's and St. Mary's counties as well as the District of Columbia.

Scattered thunderstorms with the potential for strong winds are possible in the afternoon and evening. Storms on Monday night in Howard County prompted a water rescue and fire investigation.

People who don't have air-conditioning or are spending extended periods outside will be at risk of heat-related illness, the weather service warns.

Heat Index ("feels like" temperature) for Columbia:

• 8 a.m. — 75 degrees
• 9 a.m. — 79 degrees
• 10 a.m. — 90 degrees
• 11 a.m. — 96 degrees
• Noon — 101 degrees
• 1 p.m. — 102 degrees
• 2 p.m. — 105 degrees
• 3 p.m. — 106 degrees
• 4 p.m. — 105 degrees
• 5 p.m. — 104 degrees
• 6 p.m. — 101 degrees
• 7 p.m. — 97 degrees
• 8 p.m. — 94 degrees
• 9 p.m. — 91 degrees
• 10 p.m. — 87 degrees
• 11 p.m. — 84 degrees

Heat stroke, the most serious heat-related illness, can be fatal if not treated immediately. It occurs when the body's temperature rises rapidly and the sweating mechanism fails, leading to overheating without a way to cool down.

Symptoms of heat stroke include confusion; slurred speech; seizures; hot, dry skin or extreme sweating; altered mental status; very high body temperature; and loss of consciousness/coma. If someone exhibits signs of heat-related illness, move the person to a cool, shaded area and call 911.

Stay Safe in Heat

• Reschedule strenuous activity to early morning or evening.
• Know the signs and symptoms of heat exhaustion and heat stroke.
• Wear light and loose fitting clothing.
• Drink plenty of water.

Those working outside should take frequent breaks in the shade or in an air-conditioned environment.

Temperatures will cool only slightly on Wednesday, before dropping to the upper 80s on Thursday.

Photo Credit: Shutterstock.

—By Elizabeth Janney and Greg Hambrick