Hot, muggy weather prompts Boston to issue heat advisory through Friday – The Boston Globe

The city of Boston on Tuesday issued its own heat advisory due to this week’s stretch of dangerous heat and humidity that has gripped Southern New England, sending heat index values soaring into the 90s.

The heat advisory will remain in effect from today through Friday, according to Mayor Michelle Wu’s office. The city threshold for a heat alert is three days or more of 90-degree heat index values.

“While this is not a heat emergency, we are advising people to take the necessary precautions, such as taking breaks when working outside, staying hydrated, and checking on each other in the heat,” Wu said in a statement Tuesday afternoon.

The National Weather Service had earlier extended its own heat advisory for Boston and parts of Southern New England through 8 p.m., Wednesday.

Temperatures are forecast to reach into the high 80s and low-90s Wednesday through Friday. But the heat index, or how the heat feels to the average person, will climb to near 100 through the week. The heat index, in essence, places a number on how the human body is responding to both the air temperature and moisture. When there is high moisture in the air, it makes it more difficult for the sweat mechanism that helps us cool to effectively work.

Humidity levels will also remain high into the weekend.

Extreme heat and the heavy air of humidity can cause life-threatening heat stroke or heat exhaustion if precautions, such as staying well hydrated and staying in air-conditioned areas, are not taken. Heat is the leading weather-related killer in the United States, surpassing the number of people who die in floods, hurricanes and tornadoes combined.

City officials are cautioning residents to take the heat seriously and not to wait until they feel ill to take action.

“We want to remind residents that extreme heat can be dangerous,” Adrian Jordan, the city’s chief of emergency preparedness, said. “Sustained periods of high heat increases the risk of heat stroke and other heat-related illnesses, especially for children, older adults, and those with chronic health conditions.”

Officials said the city’s Office of Emergency Management is coordinating closely with the NWS and Boston Public Health Commission to assess weather impacts on at-risk populations, “to ensure they have what they need and will be available to support any resource or coordination needs that may arise,” Jordan said.

For those city residents who are looking for ways to stay cool, the city suggested public pools, splash pads and public spots that offer air-conditioning:

• Splash pads – Open at parks and playgrounds throughout the city. A full list can be found here.

• City pools – Public pools are free. Operating hours can be found at boston.gov/pools. The BCYF Mildred pool opens tomorrow and the BCYF Perkins pool opened Monday.

• Boston Public Library – All locations and branches are available for residents to seek relief from the heat. Also, residents can participate in BPL’s summer programming for kids, teens, and adults.

Boston Emergency Medical Services typically receives a 10 to 15% increase in 911 calls during a heat wave.

Marianne Mizera can be reached at marianne.mizera@globe.com. Follow her @MareMizera.