Categorizing and naming heat waves

Arsht Rock’s initiative to categorize and name heat waves aims to increase awareness of heat’s health risks and galvanize effective responses from citizens and governments to protect lives and livelihoods.

Categorizing and naming heat waves

Heat waves have been dubbed “the silent killer” the dangers they pose wreak havoc that is largely unseen, and awareness of the human and economic devastation caused by heat waves is profoundly insufficient.

To combat extreme heat and its impact on lives and livelihoods, Arsht-Rock is piloting initiatives to categorize heat waves based on their effect on human health and to name them, much like how hurricanes, tornadoes, and winter storms are named and categorized across the world.

Because the health risks of heat waves are more severe than any other natural disaster and increasingly common, Arsht-Rock is developing innovative, location-specific warning and categorization systems that are centered on human health outcomes.

The benefits of categorizing and naming heat waves include:

  • Understanding the risks local residents face, and delivering the protection they deserve.
  • Enabling local officials to implement effective and appropriate heat risk reducing interventions
  • Improving cities’ emergency and disaster response planning.

Why is Arsht-Rock categorizing and naming heat waves?

Today, extreme heat kills up to half a million people a year worldwide. Many of these deaths are preventable with appropriate preparation and action during heat waves. Most warning systems today rely solely on weather conditions to call heat warnings. Research shows, however, that also considering the health impacts of dangerous weather, categorizing the severity of weather events, and naming the worst events increases the likelihood that people will take the actions necessary to prepare and protect themselves. For this reason, many natural disasters are already categorized and named, including hurricanes, typhoons, and tornadoes. We should be doing the same for heat, the deadliest natural disaster we face.

Improving public awareness

Stories of elderly individuals—particularly those with underlying health conditions—dying during seemingly harmless activities, like gardening, illustrate that just being outdoors can be dangerous during heat waves.   Recent research finds that younger people are susceptible to heat-related illness as well—no one is safe in the heat. In August 2021, a young couple hiking in California died on the trail amid triple-digit temperatures, making headlines and underscoring the central contradiction: people do not perceive themselves to be at risk, even during life-threatening conditions. This is supported by focus group research that finds that people tend to think of others as vulnerable, but not themselves. 

Cities can create public awareness campaigns to better communicate the dangers of extreme heat, as well as the resources available for individuals to protect themselves.

Understanding the risks local residents face

The Arsht-Rock approach is data-driven and locally unique. Arsht-Rock and local partners tailor the categorization system to individual cities and counties by analyzing decades of local meteorological and health data. Arsht-Rock’s approach accounts for location-specific variations in population demographics, the built environment, average seasonal temperatures, and heat wave duration and acclimatization, thereby uncovering the full, local impact of heat waves on mortality.

Enabling local officials to implement heat-risk interventions

When heat waves are ranked as high-risk, they are expected to be associated with large numbers of heat-related injuries. Categorizing and naming heat waves will enable local officials to implement heat-risk interventions and policies, such as opening air-conditioned shelters, activating a heat action plan, or adding extra staff to emergency rooms. 

In parallel, categorizing and naming heat waves can also serve as an integral component of a city’s emergency and disaster response planning.

How we are categorizing and naming heat waves

Arsht Rock and its team of experts analyze historic, locally-specific weather conditions and daily health and mortality data to develop unique algorithms that allow jurisdictions to estimate the human health outcomes of forecasted weather conditions. This local, historical analysis also allows us to categorize the severity of forecasted heat waves, thus giving officials an opportunity to provide the most effective, appropriate, and actionable recommendations to their citizens. Some jurisdictions may also choose to name the most severe heat waves to further underscore the need for preparedness and response. In parallel, Arsht Rock is developing recommendations to effectively message heat wave warnings and steps people can take to protect themselves.

Cities piloting heat wave categorizing and naming

Seville, Spain

Athens, Greece

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