Heat Deaths Rise 15% When You Count the Right People
Public health experts know that heat kills. But what if the way we measure heat is hiding just how deadly it really is, especially in the world’s hottest regions?
A new study published in Environmental Health Perspectives reveals that the traditional methods used to estimate temperature—like relying on airport weather stations—may significantly underestimate heat-related deaths in the Middle East. The research team, based at Harvard’s T.H. Chan School of Public Health, proposes a better method: using population-weighted temperature data that reflects where people actually live.
And the difference? It could be thousands of lives.
Why This Study Matters Now
Climate change is accelerating global heat extremes, but the Middle East is already a climate hotspot. Countries like Kuwait and Jordan face blistering summer temperatures, rapid urbanization, and often limited public health infrastructure. Yet, until now, researchers studying heat and mortality in this region have been stuck with crude tools—scattered weather stations that often sit in remote or uninhabited areas.
“Imagine assessing heat risk in New York City using only temperature data from JFK Airport,” said lead author Yazan Alwadi. “Now imagine doing that in a country the size of Jordan, with deserts, mountains, and cities all in one dataset.”
This mismatch between where people live and where temperatures are measured can distort the true relationship between heat and health.
From Desert Grids to Real Lives: A New Way to Track Heat
The study analyzed data from 152 administrative regions across 12 Middle Eastern countries, including Kuwait, Jordan, Saudi Arabia, and the UAE. Researchers compared three approaches to estimating daily temperatures:
- Station-based (e.g., one weather station per country)
- Unweighted spatial average (averaging all 1km² temperature grids equally)
- Population-weighted average (giving more weight to where people actually live)
They then linked those temperature estimates to national mortality data from Jordan and Kuwait. The results were clear: station-based data significantly undercounted heat-related deaths.
In Jordan, using population-weighted temperatures instead of station data revealed a 15% higher rate of heat-attributable deaths. In Kuwait, the difference was smaller—but still meaningful—suggesting that in more geographically varied regions, population-weighted data makes a bigger impact.
When Location Really Matters
Let’s break this down: many parts of Jordan are vast, uninhabited deserts. If one of those empty stretches reaches 45°C (113°F), it affects the national average—but not necessarily any people. Traditional averaging methods give that searing hot grid just as much weight as a crowded urban center like Amman.
Population-weighted temperature fixes this. By focusing only on the temperatures where people live, researchers create a more human-centered view of heat exposure.
It turns out that the difference in minimum mortality temperature—the point where heat risk is lowest—also shifts depending on the method used. In Kuwait, the minimum mortality temperature dropped from 30.2°C using station data to 28.3°C with population-weighted data. That means more days now fall in the “danger zone” for public health planning.
Why Public Health Can’t Afford to Ignore This
In a warming world, accurate temperature tracking isn’t just about better forecasts—it’s about life and death. Especially for regions like the Middle East, where:
- Temperature extremes are rising faster than the global average
- Air conditioning access is uneven
- Public health data is often coarse or delayed
Using the wrong kind of temperature data can undercut preparedness and mislead policymakers. The authors argue that population-weighted temperature estimates should be the new gold standard—especially for large, diverse, and understudied regions.
In fact, they’ve taken a major step toward that goal: the team is releasing an open-access database with daily population-weighted temperature records for 12 Middle Eastern countries, spanning 2003–2020.
The Bigger Picture: Heat, Equity, and Exposure
This study doesn’t just offer a technical fix. It reminds us that climate data is about people—not just pixels. When we average temperatures without considering population patterns, we risk ignoring the very communities most affected by heat.
And that has consequences: heat-related illnesses, overwhelmed hospitals, lost productivity, and excess deaths—all of which are likely to get worse as climate change continues to raise the stakes.
The researchers acknowledge that population-weighted temperature isn’t a silver bullet. It still can’t capture microclimates in dense cities or account for differences in housing quality or access to shade. But it’s a big step forward in painting a more realistic picture of who’s most at risk.
What’s Next?
This study opens new doors—and raises key questions:
- Will public health agencies in the Middle East start using these data tools in their planning?
- How can researchers in other heat-prone regions adapt similar methods?
- What infrastructure—cooling centers, heat alert systems, or urban design—should be prioritized based on more accurate temperature exposure?
As cities worldwide brace for longer, deadlier heat waves, refining how we measure heat is one small step that could lead to big changes in how we protect human health.
Join the Conversation
How does your city or country measure temperature for public health planning?
Do you think population-weighted exposure should become standard?
What kinds of local decisions could improve if we better understood who’s feeling the heat?
