Planning Magazine

Beat Extreme Heat with These 8 Tactics

America’s deadliest weather disaster calls for both mitigation and management strategies — in the hottest months and beyond. Here's how to get started today.

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Urban greening strategies like adding parks and greenways mitigate heat risk. They also provide the psychological benefits associated with access to nature, like relaxing or napping in the park, as this couple did in Phoenix. Photo by Juan Arredondo/The New York Times.

A record-breaking, sweltering heat wave continues to stretch across the country, roasting the southwestern states with no end in sight.

In the first week of June, Phoenix hit 113 degrees, marking the hottest temperature ever recorded for that time of year. This follows a string of warmer-than-normal months in the Copper State over the past two years. Meanwhile, globally, the National Oceanic and Atmospheric Administration (NOAA) reports that this April was the warmest on record, with temperatures 2.38 degrees above average, marking the 11th consecutive month of record-high global temperatures.

Heat is the deadliest weather-related hazard in the U.S. It kills more people than all others combined. It also has detrimental impacts on the economy, energy and water usage, infrastructure and ecosystems, and our quality of life.

Because of climate change, higher temperatures are impacting communities of all sizes and in all regions. But some neighborhoods are hotter than others, including districts with a history of redlining or communities of mostly low-income residents or residents of color. Certain populations are also more vulnerable to heat-related illness or death, including children and the elderly, people with chronic health conditions, people experiencing homelessness, and people who are institutionalized.

As temperatures continue to climb, cities must prepare for unprecedented heat and address these systemic inequities. To achieve equitable heat resilience, planners will need to develop a diverse portfolio of strategies.

Tactics, which fall into two categories — heat mitigation and heat management — should be prioritized to maximize co-benefits, minimize tradeoffs, and avoid maladaptive strategies that provide short-term relief but worsen the problem in the long run, like highly inefficient air conditioners that increase electricity demand and greenhouse gas emissions.

With that in mind, here are a few ideas to get you started.

Heat mitigation

When it comes to heat mitigation, the aim is to cool cities, neighborhoods, and heat-vulnerable locations. This can be accomplished through land-use planning, urban design, urban greening, and waste-heat reduction strategies that lessen the built environment's contribution to urban heat.

Because of their systemic nature, heat-mitigation strategies will likely need to be implemented across a variety of community plans, so it is important for planners to coordinate and integrate all plans and policies to advance the community's vision and goals for heat resilience.

1. Go large-scale with land-use planning. Because the built environment affects local climates, broader efforts such as conserving natural areas, developing ventilation corridors, arranging urban geometry (e.g., the dimensions and spacing between buildings), and reducing heat-trapping surfaces associated with transportation systems can be very effective.

2. Take advantage of small-scale design opportunities. Site-level design interventions like orienting buildings and streets for shade, adding shade structures, and using cool pavements, walls, and roofs can impact microclimates and affect heat at a human scale.

3. Increase vegetation. Greening tactics like urban forestry; green stormwater infrastructure; and green roofs, parks, and greenways help cool surrounding areas through evapotranspiration and by providing shade.

4. Reduce waste heat. Increasing building energy efficiency through weatherization and the use of "cool" surfaces, as well as decreasing vehicle use by encouraging transit and active transportation modes, will decrease both waste heat and greenhouse gas emissions.

Reducing individual exposure to dangerous levels of heat may require changes in public infrastructure.

Heat management

Whereas heat mitigation aims to lower temperatures and prevent future extreme-heat events from occurring, heat management is all about preparing for and responding when an extreme-heat event takes place. These types of strategies will require effective coordination across levels of government and among various disciplines and sectors, such as public health, emergency management, and the energy sector.

1. Increase access to indoor cooling. Regulations and assistance programs should be considered to help make cooling accessible and affordable to all. Energy-grid resilience is critical here because electricity used to support indoor cooling increases during extreme heat events, making "brownouts" and power outages especially dangerous.

2. Reduce exposure to dangerous levels of heat. This may require changes in the operation of public infrastructure (e.g., transit stops and hiking trails) and facilities (e.g., playgrounds), as well as in regulations for indoor and outdoor worker safety.

3. Build public awareness. As heat risks increase, it is important to work with public-health professionals to educate and inform the public about the dangers of heat and how to avoid them.

4. Create a heat action plan. Communities' emergency management systems must be prepared for unprecedented extreme-heat events, including early-warning systems, plans for coordinated responses, and designated cooling centers and resilience hubs where people can go for shelter and assistance.

This article was originally published in November 2021. 

Ladd Keith is an associate professor at the School of Landscape Architecture and Planning, University of Arizona. Sara Meerow is an associate professor at the School of Geographical Sciences and Urban Planning, Arizona State University. They are the authors of PAS Report 600, Planning for Urban Heat Resilience, and “Urban Heat Resilience,” the PAS QuickNotes from which this article is adapted.