How to Stay Cool During Extreme Heat

Hot weather and extreme heat can cause serious illness and can even be life-threatening.

During heat waves, Cambridge Police Officers will distribute cold bottles of water to residents in need while they are out on patrol. 2 people with water bottles

What is extreme heat?

Extreme heat is a prolonged period of very hot weather, which may include high humidity. In Massachusetts, a “heat wave” is usually defined as a period of three or more consecutive days above 90ºF (Fahrenheit) or 32.2ºC (Celsius). Click here to learn more about heart-related terms (e.g., heat advisory, heat warning).

How do I stay cool during extreme heat?

    2 people with water bottles
  • Know the signs of heat-related illnesses.
    • Headaches, dizziness, nausea, confusion, cramps, high body temperature, or a fast pulse are among the signs of heat-related illness.
    • If you are experiencing any of these symptoms, seek medical help immediately and move to a cooler place. Learn more.
  • Stay hydrated.
    • Keep drinking water, even if you don't feel like it. Drink two to four glasses of cool fluids every hour.
    • Avoid alcoholic drinks and too much caffeine and sugar.
    • Bring water with you wherever you go outside. Public water fountains and water refill stations are open in City parks.
  • Stay cool outdoors.
    • Limit outdoor activities to mornings and evenings when it is cooler. Be sure to decrease your overall level of physical exertion.
    • Protect yourself from the sun. Use sunscreen that is SPF 15 or higher and look for those that say “broad spectrum” or “UVA/UVB protection” on their labels.
    • Wear loose-fitting and light-colored clothing to keep cool. You can also wear a hat and sunglasses.
    • Place an extra handkerchief or neck gaiter into cold water. Wring it out so it is not dripping all over. Place or tie it around your neck. Repeat throughout the day.
    • Seek shade
    • Find Pools & Waterplay Features in Cambridge
      • Visit a sprinkler or spray park. Find one near you on the City's Waterplay Map
      • Visit a public pool. You can find local State-run pools and information about their hours here.
  • Stay cool indoors.
    • Close windows and blinds during the day.
    • Take cool showers.
    • Use air conditioning or fans. However, when the temperature is in the high 90s (or higher than 32.2ºC), fans will not prevent heat-related illnesses. If you are concerned about the cost of running your air conditioner, check to see if you are eligible to receive a discounted electricity rate from Eversource to help lower your electricity bills. Additionally, contact the City of Cambridge’s Utility Bill Helpline with All In Energy at 617-430-6230 or for assistance with accessing A/C incentives, utility bill payment help, or other energy related questions.Man playing on his phone in front of a fan
    • Stay cool by spending time in air-conditioned places like the mall, movie theater, and public libraries. View public library locations and hours.
  • Limit outdoor activities to mornings and evenings when it is cooler. Be sure to decrease your overall level of physical exertion.
  • Be a good neighbor. Be sure to check on neighbors, especially the elderly, those who live alone, those with medical conditions, those who may need additional assistance, and those who may not have air conditioning. If you or your neighbors are not vaccinated, you can call, text, video call, or meet by staying 6 feet apart to stay safe against COVID-19.
  • Children and pets should not be left in cars.
    • Never leave children or pets in a car unattended, even if running out for curbside pickup or other quick errands. Interior temperatures can rise almost 20°F within 10 minutes even with the windows cracked open.
  • Call 911 in an emergency.
    • If you or someone is showing signs of heat stroke call 911 immediately. Signs of heat stroke include:
      • A body temperature over 103 degrees; hot, red, dry, or moist skin; a rapid and strong pulse; and possible unconsciousness.
      • While waiting for help to arrive, move the person into a cool area, help cool them down with wet towels or a cool bath, and DO NOT give them fluids.

What are the signs of heat-related illness?

Heat-related illness comes in many forms, including heat exhaustion, heat stroke, heat cramps, and more. Know the signs of heat-related illnesses so that you can take care of yourself or others as needed. Some of these heat-related illnesses can be fatal and medical attention is important. To learn more about heat-related illnesses, what you can do, and when to seek medical attention, click here.

Who is at risk for heat-related illnesses

While everyone is at risk for heat-related illness, some people are at greater risk and should be sure to take special precautions, especially during this time of COVID-19. These populations include:

  • People 65 and older, children younger than two, and people with pre-existing medical conditions such as cardiovascular disease, diabetes, or respiratory illness are at greatest risk for heat-related illness.
  • People who work outside or spend a lot of time outdoors such as athletes.
  • People who may be socially isolated, including individuals experiencing homelessness and elderly residents.
  • People taking certain medications. Be sure to consult a doctor about the medications you are taking and extreme heat.
  • Those who are overweight and obese.
  • People who are pregnant. 

How can I protect family, friends, and neighbors?

  • Never leave children or pets in cars, even for a few seconds. Cars can heat up to dangerous temperatures in a very short time, even with the windows open. Make sure your loved ones drink plenty of water and stay hydrated throughout the day, including pets.Dog in a car
  • Connect with elderly neighbors and others at risk during a heat wave.  
  • Young children and people with chronic health conditions should also be monitored for heat-related illnesses.
  • Call 911 if you see someone with signs of heat stroke or clearly in need of medical assistance.

What should I do to prepare for, and help prevent, power outages?

  • Plan ahead. Have supplies in case there is a power outage including batteries, flashlights, and nonperishable food.
  • If you have life-support devices, such as home dialysis, breathing machines, or other medical equipment or supplies, that depend on electricity:
    • Talk to your health care provider about how to use them during a power outage;
    • Contact your local electric company and equipment suppliers about your power needs. Some utility companies will put you on a "priority reconnection service" list;
    • Let the fire department know that you are dependent on life-support devices; and
    • If you have medication that requires refrigeration, check with your pharmacist for guidance on proper storage during an extended outage.
  • Monitor the weather. Watch your local news or visit National Weather Service–Boston for advisories and alerts.
  • If there are advisories and alerts, fully charge your cell phone, laptop, and other electronic devices in case there is a power outage.
  • Conserve as much energy as possible to avoid power disruptions. Turn off all nonessential appliances and lights in unoccupied rooms.

What should I do during a power outage?

  • Check current power outages in the state with the Power Outage Map done by Massachusetts Emergency Management Agency.
  • Call your utility company to report power outages and learn when your power will be restored. Do not call 9-1-1 to report an outage or to ask about power restoration.
  • Stay away from downed utility wires. Always assume a downed power line is live. Call 9-1-1 to report emergencies including downed power lines or if you are dependent on equipment that requires electricity and you need medical assistance.
  • Make sure you and your loved ones stay hydrated.
  • Keep refrigerator and freezer doors closed. An unopened refrigerator will keep food cold for about four hours. A full freezer will keep the temperature for about 48 hours
  • If possible, use flashlights instead of candles. If you must use candles, place them in safe holders away from anything that could catch fire. Never leave a burning candle unattended.
  • Learn more about power outages at the state’s website.

What are some tips for wearing a mask during hot weather? 

  • Not all masks provide the same level of protection. Look for masks that fit snugly and block at least 90% of small viral particles from being breathed in. Masks should also be comfortable, especially if they are being worn throughout the day.
  • Cloth masks are best suited to outdoor use when it's easy to social distance. Most cloth masks do a good job of protecting others if you are sick.
  • Keep an extra mask with you to swap out if necessary. If your mask becomes damp with sweat, its ability to block COVID-19 could diminish.
  • If you are feeling overheated while wearing your mask, take it off for a moment and breathe making sure that you are six feet apart from others.

What are some of the heat-related terms that I should know?

  • Heat Index: A measure of how hot it really feels when relative humidity is factored in with the actual air temperature. Learn more.Sun in the sky
  • Excessive Heat Watch: Weather conditions are favorable for an excessive heat warning in the next 24 to 72 hours.
  • Heat Advisory: Daytime heat indices (plural of index) of 100ºF–104ºF (37.8ºC–40.0ºC) for two or more hours.
  • Excessive Heat Warning: Daytime heat indices of greater than or equal to 105°F (40.6ºC) for two or more hours.

Additional Resources & Links


Page was posted on 6/7/2021 3:37 PM
Page was last modified on 7/19/2022 2:23 PM
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