The National Weather Service has extended its heat advisory for Wednesday to 10 p.m. in Montgomery County, as well as the surrounding Washington and Baltimore areas.

Temperatures are expected to rise to the mid-to-high 90s, but high humidity will make it feel like a sweltering 100 degrees.

By nightfall, temerpatures were forecast to drop to the mid 70s and lower 80s. But by Thursday they're expected to creep toward 100, and will feel more like 105, according to the NWS.

Recommended ways to combat extreme heat include drinking lots of fluids, staying in the shade or indoors in air conditioning, and taking frequent breaks from strenuous work.

—Germantown Patch Editor Tiffany Arnold contributed to this story.