This StoryMap was produced in partnership with the City of Los Angeles Climate Emergency Mobilization Office (CEMO), the USC Dornsife Public Exchange, USC Environmental Health and Spatial Sciences Institute students and researchers to help build awareness among Angelenos about the increasing risks and costs from extreme heat. It is also meant to provide quick access to information on the City of LA's Heat Relief 4 LA Campaign, Emergency Management Department Programs addressing extreme heat and the City's network of cooling centers and resources.
In the following sections, you will read about heat in our city, the infrastructure changes being considered, and why some communities are more at risk and why higher temperatures alone aren't the only factors for measuring vulnerability and risk during heat waves. You will also read about the actions individuals and families can take to protect from the risks of extreme heat.
The Heat Maps: How can you interact with them?
We suggest that you zoom in and out ( + or - signs in bottom right), searching for a specific location (search bar top left) or click on the "Find My Location" circle icon (bottom right). You can also click on facilities or locations on the map for more information in pop-ups, and learn more from the linked websites.
Each map also contains a legend describing what the colors and visuals represent on the map (usually in the bottom left corner). Note that the focus of these maps is on the City of Los Angeles and surroundings, but you can click and drag or use the search bar to go to other locations if the information is available.
You should also watch these one-minute videos for a more in-depth overview on how to browse this StoryMap and how to click on and interact with the maps below in English and in Spanish.
Introduction to Heat
The Basics of Extreme Heat
Extreme heat is the most dangerous climate hazard to public health in Los Angeles and causes more deaths than any other climate hazard Nationwide. Heat waves are more frequent and have greater intensity due to the excessive extraction and use of fossil fuels and their increased use in everyday products from our clothes to single-use plastics in the food industry that have increased the demand for gas and fracking of oil and gas reserves across the globe. This increase in fossil fuel products correlates directly to climate change and extreme heat. Yet the health impacts from Extreme Heat are under-reported, as are its damages and costs to our City’s infrastructure since they are not immediately noticeable or reported, especially since heat often accompanies other climate hazards like wildfires and hurricanes.
sun shining
Extreme heat poses higher health risks because if combined with air pollution, ozone, and pre-existing health conditions in a dense population like in Los Angeles, it can more easily overwhelm the body's natural cooling mechanisms, which can escalate to heat-related illnesses such as heat exhaustionor heat stroke and also premature death very quickly.
Extreme Heat is Los Angeles' Most Lethal Climate Risk
Streets of Los Angeles
Heat exposure is distributed unevenly across L.A County. Photo by Alexis Balinoff on Unsplash.
Extreme heat is the most hazardous climate risk for Los Angeles, due in part to population density, concrete built environment, and lack of tree canopy, and open space. The pollution also leads to greater exposure coupled with additional pre-existing health conditions and lack of thermal cooling from a lack of cooling systems, in most homes in Southern California, then the risks are even higher.
By 2050, we expect L.A. to experience 31% more extreme heat days. As global temperatures rise, extreme heat events are more frequent and last longer worldwide, becoming an even greater risk to public health, biodiversity, and our public and private infrastructure. In Los Angeles, the effects are already evident, with 5 more times the heat waves than just 10 years ago. The truth is these numbers are becoming more unpredictable as records break every heat season.
In Los Angeles, hotter, longer heat waves are now extending to mid-November, sending more people to the hospital, thus also causing more deaths than any other climate hazard.
In the next 30 years, scientists predict that every neighborhood in Los Angeles will face many more days where temperatures soar above 95°F. Areas that already have a lot of hot days will see even more, with inland valley communities expected to have twice as many extreme heat days by 2050.
Uneven Impacts of Heat
Heat disproportionately affects low-income residents and communities of color, many of which are also pollution burdened and are identified in the CalEnviroScreen 4.0 maps since these are historically disinvested areas of the City. Due in part to the lack of open space trees and vegetation and lack of permeability in the soil, these communities also face heightened vulnerability to extreme heat-related illness and death due to higher rates of pre-existing health conditions, inequitable access to cooling systems, key health care and heat relief resources in their neighborhoods, living in urban heat islands and neighborhoods with greater pollution burden. Many of them also work outdoors and in indoor settings with greater exposure to heat or fewer protections.
Individuals are more vulnerable to the harmful health effects of extreme heat if they have pre-existing health conditions, are children or elderly, or are pregnant, take certain medications, and are unhoused.
A UCLA heat risk equity analysis revealed that neighborhoods at highest heat risk are largely concentrated in the San Fernando Valley, South Los Angeles, and the South Bay portions of the City of LA - areas which already experience cumulative burdens of pollution, housing insecurity, and pre-existing health conditions. What is called for and necessary is to create Climate Vulnerability Maps or Heat Risk Maps at the State and Federal Level to identify where we can invest more resources to save more lives.
L.A.'s Climate Emergency Mobilization Office
The combination of extreme heat and weather, air pollution, coupled with the cumulative impacts and disparate impacts on frontline communities in the City of Los Angeles, inspired the creation of the Climate Emergency Mobilization Office (CEMO) as well as the position of Chief Heat Officer, the first on the West Coast.
CEMO is guided by the principles of environmental and climate justice and collaborates with various City Departments and Bureaus, LA County, the State of California and many CBO's. Through meaningful community engagement and in partnerships with communities across Los Angeles, CEMO seeks to mitigate climate emergencies such as extreme heat to reduce heat injury and death as well as to advise on equitable climate solutions. CEMO’s mission is to drive the co-creation of equitable climate and extreme heat solutions for a resilient, thriving, healthy City of Los Angeles for all.
Heat Risks & Impacts on Infrastructure
Extreme heat is significantly impacting Los Angeles in various ways, affecting mobility, nature, tree canopy, public health, how we work and exercise outside and last but not least, our infrastructure, and all of this is having long term effects on our economy, liveability, and mobility as pedestrians and cyclists. We don’t want to live in or imagine a future where it's too hot to walk, bike and take public transportation.
At Home
With heat waves now stretching into November, many households struggle to keep cool. Inadequate or costly cooling systems mean residents simultaneously battle dehydration, discomfort, poorer indoor air quality, and thus suffer increasingly from pre-existing health conditions.
People experiencing homelessness are reported to be 50% of those who perish during heat waves nationwide as being out in the elements without protection and hydration exacerbates their risk. During the 2022 heat waves in Los Angeles County, people without secure housing were more than 50 times more likely to die a heat related death than the general population.
Felisa Benitez, 86, wipes the sweat from her brow while taking a break from cleaning her electric fan on the porch of her home at the San Fernando Gardens public housing complex in Pacoima.(Genaro Molina / Los Angeles Times)
During Commutes
Commuters can be exposed to extreme heat particularly when reliant on public transit. Whether it's walking under the blazing sun or waiting at bus stops with minimal shade, many residents endure prolonged periods of heat exposure during their daily journeys. Excess heat exposure can sometimes result in heat-related illnesses or accidents while commuting. Enhancing infrastructure, such as providing more shade at bus stops, increasing tree canopy, and improving cooling options for public transportation, is crucial to mitigating these risks and ensuring the safety and comfort of commuters throughout the city.
People board a Metro bus at a bus stop with no shade on Lankershim Boulevard near Victory Boulevard in North Hollywood. (Mel Melcon/Los Angeles Times)
Our Health
In Los Angeles, the intense heat is taking a toll on the health of residents across the city. Exposure to high temperatures increases the risk of dehydration, heat exhaustion, and heatstroke, especially for vulnerable groups.
Pregnant people or those with pre-existing conditions are particularly vulnerable, for example, people with asthma, kidney or other chronic diseases. As such, health services may get strained during heat waves resulting in longer waits in emergency rooms and increased healthcare costs.
An analysis by the Los Angeles Times estimated that nearly 4,000 excess deaths between 2010 and 2019 could be related to extreme heat during heat waves.
Intense heat takes a toll on the health of Los Angeles residents; heat-related illness; extreme heat; Urban Heat Island Effect
Challenges to Infrastructure
Extreme heat can also affect critical infrastructure such as roads, metro systems, water supply and power lines, etc. and their ability to operate.
L.A.'s water supply. When it gets very hot, increased evaporation from reservoirs combined with increased water usage for things like watering plants, showers, and outdoor activities (e.g., pools and splash pads) can stress the water system and lead to shortages.
L.A.'s power grid. When temperatures rise, people use more electricity to cool their homes, straining the power system. By understanding electricity demand during heat waves, we can plan new and upgrade existing infrastructure to better withstand high temperatures and reduce the risk of power outages during heatwaves.
Heat Disrupts Work and Increases Costs
The impact of heat on Los Angeles extends to every part of the city's economy. Workers from agriculture, manufacturing, and construction sectors are particularly affected. This means that workers in jobs that require physical labor and long hours outdoors are also more likely to experience productivity, wage losses and losses from medical emergencies due to extreme heat.
Construction and utility workers, for example, spend about two thirds of their working hours outside, making them highly vulnerable to heat-related stressors. Informal workers, who may not be accounted for in official data, many of whom also work outdoors and play a vital role in the city's economy are also at greater risk.
A survey by the USC Dornsife found that over one in four Los Angeles County workers highly exposed to heat reported not receiving paid sick leave or extra break time during hot days. This heat-related loss in productivity costs the city nearly $5 billion annually, a significant portion of its budget, and this figure is expected to double by 2050 (USC Dornsife LA Barometer, 2021).
Why is L.A. Vulnerable to Extreme Heat?
Global Warming & Urban Heat Islands
Our planet has already warmed an average of 1.1°C (1.9°F) since the industrial revolution (1880). While this may seem small, this is already causing significant impacts - from more frequent hurricanes to longer and more extreme heat events.
As the planet warms, urban areas are warming even faster than the rural areas surrounding them due to human activities and infrastructure. Buildings, roads, parking lots, and other structures absorb and retain heat from the sun, while the lack of vegetation and increased energy usage further contribute to the temperature rise. This phenomenon leads to higher temperatures in urban areas compared to nearby areas, especially during hot summer days and nights. Neighborhoods in a highly-developed city can experience mid-afternoon temperatures that are 15°F to 20°F hotter than nearby tree-lined communities or rural areas with fewer people and buildings. The heat island effect can worsen air quality, increase energy consumption for cooling, and pose health risks to residents.
Urban Heat Island Effect; Extreme heat with increasing intensity downtown
The graphic to the rightshows how different types of land cover, like buildings, roads, and green spaces found in natural or urban areas, can affect temperatures in the day time and night time.
Heat Risk & Equity
Like climate change, extreme heat is inherently unequal as it impacts the low income and pollution burden pollutions of LA the most.
Communities of color face a disproportionate burden from the extreme heat, pollution, and pre-existing conditions. This inequity can be traced back to historical urban planning practices such as redlining, the construction and placement of state highways near low income residential areas, and targeting urban renewal projects unequally, which shaped the lack of distribution of green spaces and impermeable surfaces in minority and low income neighborhoods.
CEMO is considering the intersection of all these historical factors and current day social and physical conditions Angelenos are facing in developing its Equity Index Priority Scores which help highlight communities that may have the highest need for certain investments. Read more and explore the Los Angeles Measure of Access, Disparity and Equity (MADE) Indexhere.
Formerly redlined areas in LA, including neighborhoods like South Central, Boyle Heights, and parts of East LA, were often targeted for industrial development and highway construction, leading to increased heat-absorbing infrastructure and higher levels of environmental hazards like air pollution from heavy traffic. Although gentrification and urban redevelopment have altered the landscape of these neighborhoods in recent years, it's crucial for LA to address this history of environmental injustice and prioritize equity in its efforts to enhance resiliency and mitigate the impacts of urban heat islands.
Zoom in or type in an address in the search bar for a closer view of your neighborhood, and zoom out or drag the map to explore any other region within the United States.
Urban heat island severity in the City of Los Angeles, showing a relative measure where darker pink pixels are higher on the severity scale than lighter colored pixels within the same city.
Heat Vulnerability
An individual’s vulnerability to heat isn't determined just by exposure to high temperatures in the places where you live, work, commute, and spend time. It also depends on an individual'sunderlying health conditions, sensitivity to heat, the environmental burden they experience in their neighborhoods, and their access to cooling or relief resources during periods of extreme heat.
The maps below illustrate the cumulative burden of pollution from multiple sources (air pollution, traffic and diesel pollution, water contamination, solid waste facilities, etc.), population vulnerability, and heat-related illnesses. The pollution burden score was obtained from CalEnviroScreen 4.0, which is an environmental justice screening tool developed by the California Office of Environmental Health Hazard Assessment to score and rank the cumulative impact of environmental pollution along with factors that increase a population's vulnerability to their adverse health effects (including existing illnesses, linguistic isolation, poverty and more). The vulnerability score is shown in the Population Characteristics map. And finally, the heat-related illnesses map displays the daily surplus of emergency room visits per 10,000 people living in each neighborhood of California that are attributed to extreme heat.
POLLUTION BURDEN
CalEnviroScreen 4.0's Pollution Burden score reflects a neighborhood's cumulative exposure to several pollutants.
Airborne particulate matter, lead in water and soil, proximity to waste processing facilities, and a host of additional indicators were all considered in this pollution burden score.
Population Vulnerability
CalEnviroScreen 4.0's Population Characteristics Percentile map considers both underlying health and socioeconomic factors that increase a population's susceptibility to adverse environmental and climate-related exposures such as heat. Rates of cardiovascular disease, asthma, poverty, educational attainment, and a variety of additional variables were used to create these percentile scores.
HEAT RELATED ILLNESS
UCLA's map of excess emergency room visits on days of extreme heat paints a broad picture of population vulnerability to extreme heat.
Excess emergency room visits per 10,000 people were summarized at the zip code level. Visit UCLA's maps to learn more.
Factors that Increase Heat Risk
The CDC identifies certain groups at the highest risk of heat-related illnesses, including older adults, young children, and individuals with mental illness or chronic diseases (CDC, 2024).
Brick building in Los Angeles Arts District
Metal fan on wooden floor
Outdoor temperature thermometer over 100 degrees fahrenheit
On days with extreme heat, access to basic cooling resources can be life-saving especially for the elderly or individuals with lower mobility.
Individuals without access to reliable transportation
Non-English speakers
Other Occupations or Activities
Outdoor workers
Other essential workers who may not be able to stay home on extremely hot days
Athletes and outdoor recreators
Los Angeles Heat Action and Resilience Plans
The City of Los Angeles is considering all of the above factors in the five tracks of its proposed Heat Action and Resilience Plan (HARP). CEMO recently launched the planning of the HARP with community members.
The five tracks in the LA CEMO heat action and resilience plan
The five tracks in the LA CEMO Heat Action and Resilience Plan (HARP)
To help keep communities safe and healthy, the City of LA's Chief Heat Officer Marta Segura and her at CEMO have announced a Heat Action framework that will address LA's resilience for the built environment, community preparedness, Heat Response and City Development of emergency resources, nature-based solutions, and added a track to ensure there was monitoring and accountability of the agreed upon strategies.
Heat Adaptation in the Built Environment
The City is working to build a healthier urban environment through:
Shade Equity.Access to shade at bus stops and streets through shelters and tree canopy.
Cooling & Resilience Centers.More locations that can provide relief from extreme heat during emergencies and every day needs.
Hydration Stations.Access to water fountains.
Passive Cooling & Building Electrification.Modifying buildings to better withstand temperatures by installing more green materials and making buildings work more energy efficiently.
Bus shelter with CEMO heat campaign poster in Los Angeles, CA next to Bill Rosendahl Del Rey Park.
Extreme Heat Public Preparedness and Emergency Response
The City of L.A. supports:
Annual Heat Awareness Campaign.Increasing public awareness of the dangers of heat through billboards, signage and community engagement.
Early Notification System. Early warnings (like phone alerts) of extreme heat help prevent heat injuries and illness.
Response Plan and Training with Emergency Services.Supporting integrated preparedness and planning within the emergency response department.
Metro bus with LA City's CEMO #HeatSafeLA campaign
Nature-based Solutions & Greening
Increasing the amount of nature in urban areas can provide significant cooling benefits, while providing cleaner air and healthier communities.
Equity-Focused Tree Planting. Recognizing that trees are unequally distributed in L.A., the City is prioritizing new tree plantings to communities that lack shade.
Green Stormwater Infrastructure.By decreasing the amount of pavement across L.A., the City is supporting better ground water storage from rain and increasing urban cooling.
Street of Los Angeles
What You Can Do
Plan, Prepare, and Check in on others
You can take the following steps to keep yourself and your family and neighbors safe during a heat emergency.
Before - Stay Prepared and Informed
The first line of defense is knowledge: Stay informed about heat emergencies through local news and weather reports, and CEMO's newsletter, blog, and official social media accounts (find them all here).
If you feel too hot, go somewhere cool and rest, like a cooling center.
Wear light-colored, lightweight clothing that breathes.
Take cool showers.
Avoid direct sunlight and limit caffeine.
Drink more water and carry a reusable water bottle.
Visit the resources listed above.
Listen to your body! Learn the warning signs of heat illness: heavy sweating, clammy skin, cramps, tiredness, dizziness, headaches, nausea, confusion, high body temperature. If you experience these symptoms and suspect heat stroke, call 911 and seek medical attention immediately.
During - What Households Can Do
Check on neighbors who might be vulnerable to the heat, especially those without air conditioning.
Never leave children or pets in a car - not even for one minute. Temperatures inside a car can quickly skyrocket to deadly levels.
Don't forget the pets! Keep pets indoors if possible. If kept outside, give them plenty of water and shade to rest in.
Watch this Video with Helpful Tips
LA This Minute - Tips to Beat the Heat
City of Los Angeles Resources
Visit CEMO’s Heat Relief Resources page for more information about City of LA Heat Relief Programs, Heat Safety Communications, and more.
Cool Spots LA App
Cool Spots LA shows Angelenos where they can go to cool off during emergencies, such as our recent extreme heat waves. CEMO coordinated the efforts of LADWP, StreetsLA, the Department of Recreation and Parks (RAP), Los Angeles Public Libraries (LAPL), and the Office of the Mayor to map all of the augmented Cooling Centers, libraries, senior centers, recreation centers, shade structures, bus shelters and hydration stations throughout LA.
A cooling center is an air-conditioned public building, set up to provide relief and safety for the public during heat waves. During extended periods of extreme heat, City of LA will dedicate regional cooling center locations around the area. These “augmented” sites with expanded hours of operation are usually at LA Recreation and Parks facilities. However even during periods of lesser heat, all park locations also offer shelter from adverse weather during regular business hours. Interact with the Cool Spots LA app below to find the nearest pools and splash pads, cooling centers, hydration stations, and more.
Responding to the impacts of extreme heat will require efforts across the City of Los Angeles. CEMO is creating an equitable Heat Action and Resilience Plan (HARP) to lead to a healthy and thriving LA. CEMO is also coordinating with the Department of the City Planning’s efforts to develop a Climate Vulnerability Assessment and Adaptation Plan.
