Extreme heat happens with temperatures over 90 degrees for a few days or more and usually involves high humidity. High temperatures increase the risk of heat-related illness and can make chronic health conditions worse.
Here are tips for staying cool and safe on hot days.
- Wear light-colored clothing to keep cool—dark colors absorb the sun’s heat.
- Wear a hat, sunglasses, and use sunscreen of SPF 15 or higher 30 minutes before you go out. Look for sunscreens that say “broad spectrum” or “UVA/UVB protection” on their labels.
- Stay cool indoors. Use air conditioning or find places in your neighborhood where you can cool off, such as a library or shopping mall. Fans will not prevent heat-related illnesses during extreme heat.
- Take a cool shower.
- Try to limit outdoor activities to mornings and evenings on hot days.
- Visit a sprinkler or spray park, or a public pool like the City’s Gold Star pool or a State-run pool.
- Check out these additional tips from the CDC on staying cool in extreme heat.
- Drink enough water! Try to avoid alcoholic or very sugary and/or caffeinated beverages because they can dehydrate your body. Remember to drink water or sports drinks before, during, and after exercising.
- Give your pets plenty of fresh water and leave the water in a shady area.
- Use a reusable water bottle for filling up if on the go. Did you know that Cambridge has water bottle fillers in most parks and squares?
- Know the signs of heat-related illnesses, how to treat them, and how to prevent them.
- Monitor the weather. Watch your local news or visit National Weather Service–Boston for advisories and alerts.
- Take action now. Ready.gov gives recommendations on precautions you can take at home before and during periods of extreme heat.
- Learn which of your medications can make you more sensitive to the sun and heat.
Take Care of Others
- Never leave children or pets in cars! Cars can heat up to dangerous temperatures in a very short time, even with the windows open. Children and babies left in parked cars are at greatest risk of getting heat stroke or dying.
- Keep pets safe with these tips. If the sidewalk or asphalt on the street is hot to your hand, it’s too hot for pets’ paws. Take that walk when the ground cools down.
- Check on elderly neighbors twice a day 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. What to look for: high temperature; hot red, dry, or damp skin; fast, strong pulse; headache; dizziness; nausea; confusion; and losing consciousness (passing out). Heat stroke can be fatal, so it is important to get immediate medical attention.
What are some heat-related terms 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 about the heat index.
- 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 100°F–104°F (37.8°C–40.0°C) for two or more hours.
- Excessive Heat Warning: Daytime heat indices of greater than or equal to 105°F (40.6°C) for two or more hours.
Adapted from the Centers for Disease Control and Prevention’s Tips for Preventing Heat-Related Illness and Warning Signs and Symptoms of Heat-Related Illness.
Updated August 3, 2022