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This page includes information about the health risks of extreme heat, tools and tips to help you stay cool, links to get help paying for utilities, and other local resources.

Who’s at risk

People at higher risk

People aged 65 years or older

Older adults are less likely to sense and respond to changes in temperature. Many people don’t feel thirsty until they’re already dehydrated. If you’re older, be sure to drink water during extreme heat. Others should check in on older adults to make sure they’re staying cool and hydrated.

Older adults who have questions about the heat can call the Philadelphia Corporation for Aging’s Helpline at (215) 765-9040.

Infants and young children

Young children (under age 4) are sensitive to the effects of excessive heat. If you care for young children, they’re relying on you to stay cool and hydrated.

People with certain chronic medical conditions

Many prescription medications can contribute to dehydration. They may also affect the body’s ability to regulate body temperature. These medications include antihistamines, beta blockers, and drugs used to treat mental illnesses like depression and schizophrenia. Ask your healthcare provider how extreme heat events may affect you.

People with certain chronic conditions are also at high risk. Common risks include diabetes, cardiovascular disease, and asthma. People with these conditions are less likely to sense and respond to changes in temperature.

  • Diabetes: People with diabetes get dehydrated more quickly. High temperatures can change how your body uses insulin. If you have diabetes, you may need to test your blood sugar more often. This will help you adjust your insulin dose and what you eat and drink.
  • Cardiovascular disease: People with heart disease may be more vulnerable to heatstroke. Some medicines used to treat high blood pressure, like diuretics (water pills), can make dehydration worse.
  • Asthma and other respiratory diseases: High temperatures can affect air quality. People with asthma and other breathing problems may have worse symptoms during high temperatures.

You may need to stay indoors or visit a cooler location when it’s hot. Check air quality ratings so you can make a plan.

Neighborhoods at higher risk

Some Philadelphia neighborhoods are hotter than others. Identifying those neighborhoods helps the City keep people safe during very hot weather.

The Philadelphia Heat Vulnerability Index shows which areas in the city are hottest and coolest during the summer. The index was created by the Philadelphia Department of Public Health and the Office of Sustainability.

Some of the hottest neighborhoods in Philadelphia are:

  • Cobbs Creek.
  • Point Breeze.
  • Strawberry Mansion.
  • Hunting Park.

Affected neighborhoods are hotter because they have:

  • Lower tree canopies with younger, shorter trees.
  • Fewer green spaces.
  • More exposed asphalt and dark surfaces, including black roofs.
  • Older, less weatherized homes, largely due to a history of redlining and lack of investment.

How to stay safe

Muscle cramps may be the first sign of heat-related illness.

Symptoms may include:

  • Heavy sweating.
  • Painful muscle spasms, often in the abdomen, arms, or calves.

What to do:

  • Stop activity and move to a cooler location.
  • Drink water.
  • Seek medical attention if cramps persist for more than one hour.

Heat exhaustion can develop after several days of exposure to high temperatures and inadequate replacement of fluids. People are most prone to heat exhaustion if they:

  • Are 65 years old or older.
  • Have high blood pressure.
  • Work or exercise in a hot environment.

Symptoms may include:

  • Heavy sweating.
  • Headache.
  • Weakness.
  • Fatigue.
  • Dizziness.
  • Fainting.
  • Nausea.
  • Vomiting.

What to do:

  • Go to an air-conditioned space. On especially hot days, the City opens cooling centers.
  • Sip cool, non-alcoholic beverages.
  • Take a cool shower or bath.
  • Rest.
  • Seek medical attention if symptoms persist for more than one hour.

Heatstroke is the most serious heat-related illness. Heatstroke can cause death or permanent disability without emergency treatment.

Symptoms may include:

  • Very high body temperature (above 103°F).
  • Red, hot, dry skin (no sweating).
  • Confusion.
  • Throbbing headache.
  • Nausea.
  • Unconsciousness.

If you see someone with these symptoms, call 911 immediately. This is a medical emergency.

Tips to stay cool

In a heat health emergency, you can visit cooling centers, pools, and spraygrounds. You can also call the Heatline at (215) 765-9040 for advice on staying cool and information on emergency services.

Stay hydrated:

  • Drink plenty of water. Don’t wait until you’re thirsty to drink.
  • Avoid alcohol, caffeine, and sugary drinks.

When you’re outside:

  • Avoid working, exercising, or playing outside during the hottest part of the day (usually noon to 5 p.m.).
  • Slow down. Rest in the shade or a cool place when you can.
  • Wear lightweight, light-colored, and loose-fitting clothes.
  • Wear a wide-brimmed hat or use an umbrella for shade.

At home:

  • Use air conditioners and fans. If you use a fan, make sure your windows are open to release trapped hot air.
  • Use drapes, shades, or awnings in your home. Outdoor awnings can reduce the heat that enters the home by up to 80 percent.
  • Take a cool shower or bath.
  • Visit a friend with air conditioning or spend time in a cool place like a mall, library, senior center, or cooling center. Even a few hours in air conditioning during the hottest part of the day can help your body recover.


  • Never leave older people, children, or pets alone in cars.
  • Check on older adults who live alone.

Fire hydrants:

Fire hydrants are for fighting fires. Opening hydrants to cool off decreases water pressure. This makes it harder for Philadelphia firefighters to do their jobs. It can also damage water mains. If you see an open hydrant, call the Water Department’s emergency line at (215) 685-6300.

Help with utility bills

These programs can help you pay your utility bills to keep your home cool:

Extreme heat events

During very hot weather, the City may declare a heat health emergency.

In a heat health emergency:

  • A special Heatline is open for calls: (215) 765-9040. Call the Heatline to get health safety tips and talk to a nurse about medical problems related to the heat.
  • Cooling centers stay open later.
  • Mobile heat health teams may be dispatched.
  • Residential utility shutoffs stop.

If you think someone is having a medical emergency, call 911.

Emergency notifications

Sign up for ReadyPhiladelphia to get text and email notifications about heat and other emergencies. The alerts are free, but your wireless provider may charge for text messaging.

Code Red

During very hot weather the City can declare a Code Red to protect people who are homeless. A Code Red also affects pet care.

For people who are homeless:

  • Call the outreach team at (215) 232-1984 if you see someone on the street who needs help.
  • Call 911 if there is a medical emergency.

For pets:

  • All dogs must have shade to protect them from the sun. If you do not provide your dog shade, you could face a fine of $500 or more.
  • To report a dog left outdoors in very hot weather, call the Animal Care & Control Team (ACCTPhilly) at (267) 385-3800.

Why it’s getting hotter

Climate change

Since the Industrial Revolution, human activity has been the main cause of climate change. In the 1880s, farming societies started using machines and building factories. These new industries increased the need for fuel — which continues to the present day. Burning fossil fuels releases greenhouse gas, which traps heat in Earth’s atmosphere.

Today, the planet is warming faster than ever. This is causing serious changes to our environment. The average temperature has risen by 3.4 degrees Fahrenheit since 1970, according to the National Oceanic and Atmospheric Administration.

What this means for Philadelphia

From 1971 to 2000, Philadelphia had an average of four days per year that reached 100°F. By 2099, experts predict that 55 days per year will reach 100°F.

Hotter days may bring more heatwaves. These extended periods of hot weather are worse in cities like Philadelphia. This is due to the heat island effect — a term for the way that cities trap heat because of buildings, roads, and other structures.

Risks to Philadelphia

Philadelphia is at risk for:

  • Increased heat.
  • Increased precipitation, flooding, and severe storms.

These effects are felt differently across the city. Lower-income neighborhoods and communities of color are more likely to be harmed by the changing climate.

In Philadelphia, some neighborhoods can get as much as 22°F hotter than others. These neighborhoods have more low-income residents and residents of color than other neighborhoods.

This pattern of unequal exposure to risk tells us that climate change is not only a public health issue. It’s also a racial and social equity issue.

What the City is doing

The Office of Sustainability is leading the City’s efforts to address climate change. They’re working with partners to:

  • Improve the quality of life in all Philadelphia neighborhoods.
  • Reduce carbon emissions.
  • Prepare Philadelphia for hotter, wetter weather.

Beat the Heat

Hunting Park is one of Philadelphia’s hottest and most heat-vulnerable neighborhoods. In 2018, the Office of Sustainability worked with residents to support community-driven decisions about how to respond to extreme heat. Hunting Park residents informed the City’s first community-driven resilience plan, Beat the Heat Hunting Park: A Community Heat Relief Plan.

Office of Sustainability continues to work with community leaders and City departments to prepare Philadelphia for extreme heat and other climate change effects.

You can start your own Beat the Heat project in your neighborhood. Get all the tools you’ll need in the Beat the Heat toolkit.

Other City programs focused on climate change

TreePhilly is an urban forestry program of Philadelphia Parks & Recreation and Fairmount Park Conservancy. Trees and greenspace absorb carbon, the main greenhouse gas behind climate change. They can provide relief from heat through shade and evapotranspiration.

Green City, Clean Waters is a 25-year plan to restore local waterways. It uses plants and trees to absorb harmful stormwater before it pollutes our rivers.

Solarize Philly is a rooftop solar program of the Philadelphia Energy Authority. Switching to renewable systems like solar power is a critical part of reducing greenhouse gas emissions and making energy sustainable.

Learn more


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