As temperatures and humidity continue to soar, the Massachusetts Emergency Management Agency (MEMA) has issued a heat advisory for much of the state.

"A heat advisory means that a period of hot temperatures is expected," the agency said in a statement released today. "The combination of hot temperatures and high humidity will combine to create a situation in which heat illnesses are possible."

The heat index value was expected to range from 100 degrees up to 104 in the heat advisory areas, as ambient temperatures stretched between 90 and 95 and dew points reached for the lower 70s.

Affected areas include Norfolk and Northern Bristol counties, as well as Eastern Franklin, Eastern Hampden, Eastern Hampshire, Worcester, Middlesex, Essex, Suffolk, and Plymouth counties.

MEMA is also advising of scattered thunderstorms that are expected to develop during the afternoon and continue into the evening.

"The thunderstorms will likely contain torrential downpours and isolated flash flooding is a possibility," MEMA said. "A few thunderstorms may also contain strong wind gusts. A wet microburst or two is a possibility this afternoon and evening. Lightning will also pose a risk for some outdoor activities this afternoon and early evening."

The National Weather Service headquartered in Taunton has also issued a heat advisory, and urges people to drink plenty of fluids, stay in air-conditioned spaces, and stay out of the direct sun as much as possible.

Also, the NWS said, "take extra precautions. If you work or spend time outside, when possible reschedule strenuous activities to early morning or evening, know the signs and symptoms of heat exhaustion and heat stroke, wear lightweight and loose fitting clothing when possible and drink plenty of water."

"To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments," the NWS said. "Anyone overcome by head should be moved to a cool and shaded location."

Heat stroke is an emergency, the agency said, and 9-1-1 should be called.


Sweltering weekend ahead

Both MEMA and the NWS are further warning of a high expectation for much of the same conditions through the weekend.

Temperatures may be a little cooler across eastern Massachusetts on Saturday, MEMA indicates, "but the humidity will remain high."

"More thunderstorms will likely develop Saturday afternoon and persist into the evening. There will be a risk of torrential downpours with these thunderstorms, and a few thunderstorms may produce flash flooding," MEMA advised. "A few thunderstorms may also be strong to severe, with a threat of localized wind damage. Lightning will likely again pose a risk for some outdoor activities."

Sunday is not anticipated to bring relief, with all of the advisory areas, except the south coast, likely having heat indices near or slightly above 100.

"Scattered thunderstorms are expected to develop, possibly most numerous along and south of the Mass Pike," MEMA said. "Localized flash flooding, strong wind gusts, and lightning will again be threats for Sunday afternoon."


Extreme heat safety tips

MEMA offers the following safety tips for extreme heat events:





*For more heat safety tips, visit: www.mass.gov/mema/heat