Extreme Heat

During extreme heat, the City of Boston will likely declare a heat emergency and will often extend pool hours in addition to opening cooling centers. The City asks that you check on your neighbors, especially the elderly to ensure they are okay. For up-to-date information call the Mayor's 24 Hour Hotline at 617-635-4500.

Conditions that can induce heat-related illnesses include stagnant atmospheric conditions and poor air quality. Consequently, people living in urban areas may be at greater risk from the effects of a prolonged heat wave than those living in rural areas. Also, asphalt and concrete store heat longer and gradually release heat at night, which can produce higher nighttime temperatures known as the "urban heat island effect."



Prepare your home:
  • Install window air conditioners snugly; insulate if necessary.
  • Check air-conditioning ducts for proper insulation.
  • Install temporary window reflectors (for use between windows and drapes), such as aluminum foil-covered cardboard, to reflect heat back outside.
  • Weather-strip doors and sills to keep cool air in.
  • Cover windows that receive morning or afternoon sun with drapes, shades, awnings or louvers. (Outdoor awnings or louvers can reduce the heat that enters a home by up to 80 percent.)
  • Keep storm windows up all year.


Elderly residents are particularly vulnerable to heat-related illnesses and injuries, but everyone should remember these tips to beat the heat:
  • Limit their activities during very hot weather
  • Drink plenty of fluids
  • Avoid beverages that contain caffeine or alcohol
  • Avoid cooking
  • Take cool showers or baths
  • Wear loose, light-colored clothing.


Be mindful of warning signs for heat illness, which include:
  • Dizziness
  • Weakness
  • Fainting
  • Vomiting
  • Stomach cramps
  • Cramping of the legs or arms
  • Confusion and agitation.


If anyone experiences any of the symptoms listed above, they should first stop what they are doing and, if possible, move themselves to a cooler area. If symptoms persist, call 9-1-1 immediately.

News & Press Releases »

Preparedness Tools

Multimedia & Downloads »

Social Media »