The Heat Will Kill You First Summary

"Heat is the prime mover of climate chaos, melting ice, drying soil, and even reviving ancient bacteria from thawed permafrost." This book explores how rising temperatures threaten humanity and the environment—and how we can adapt.

1. Climate Change is Already Here

Heatwaves, once considered rare in certain regions, are now becoming a deadly reality. The 2021 Pacific Northwest heatwave, with temperatures soaring to 121°F in some places, disrupted both ecosystems and human lives. Over three days, over 1,000 people died, salmon collapsed from overheated rivers, and baby hawks leaped to their deaths.

Heatwaves intensify natural disasters and ecological shifts. Ice melts rapidly, flooding nearby towns, while wildlife migrates or perishes. Vegetation, vital for carbon absorption, suffers dehydration under the relentless sun.

This new normal has roots in human activity. Burning fossil fuels releases heat-trapping gases like CO2, accelerating global warming. Rich nations may adapt better, but inequality exposes underprivileged groups to greater harm.

Examples

• The town of Lytton, British Columbia, was destroyed by fire when temperatures reached 121°F.
• Over a billion sea creatures perished in a three-day heatwave in the Pacific Northwest.
• The economic cost of heatwaves from the 1990s to 2021 has exceeded $16 trillion.

2. Heat Shaped Human Evolution

Human survival depended on adapting to and managing heat. Early humans evolved mechanisms like walking upright to stay cool on African savannas and developed unique sweat glands to regulate body temperature through evaporation.

Sweating gave humans an edge for endurance hunting. With hair loss, except on the head for sun protection, humans could chase prey during the hottest parts of the day, outlasting other animals forced to rest.

Animals also adapted uniquely. Camels used their humps for insulation and fat reserves, while Saharan ants scavenge during times predators can't bear the heat. Still, the adaptive edge isn’t enough to counteract radically changing climates.

Examples

• Eccrine glands evolved to make sweating efficient, helping early humans cool down while running.
• Camels’ humps allowed them to endure desert heat by storing fat for energy, not water.
• Silver ants in the Sahara thrive by foraging during intense midday heat when predators can’t.

3. Heat and the Human Body

Human bodies constantly produce and regulate heat. When temperatures or humidity rise too quickly, the body’s mechanisms to cool down, such as sweating, can fail, leading to dangerous conditions like hyperthermia or heatstroke.

Dehydration exacerbates heat’s effects. Just a 2% reduction in body water can strain the heart and impair blood circulation, making it harder to stay active or even survive in extreme conditions. Beyond hydration, core body temperature management through external cooling is critical.

Heat doesn’t just affect physical health—it’s a killer in extreme weather. Without adequate response measures, urban or rural environments become dangerous battle zones against heat exposure.

Examples

• In humid climates such as Chennai, people struggle to sweat, raising their risk of deadly overheating.
• Extreme activity in hot environments can dehydrate individuals by up to three quarts of water per hour.
• Hyperthermia survivors often require emergency treatment involving ice or cold water immersion.

4. Urban Heat Islands are Deadly

Cities trap heat due to materials like concrete and asphalt, which absorb and retain heat. Urban areas can be up to 20°F hotter at night compared to surrounding rural locations, creating what's called the urban heat island effect.

Urban heatwaves overwhelm unprepared cities. A blackout in such conditions could paralyze transport, water, and medical systems, creating chaos. Furthermore, slum dwellers and outdoor workers are at higher risk due to lack of shade or air conditioning.

Cities like Phoenix, with 339 heat-related deaths in a single year, are becoming increasingly hostile environments, forcing planners to rethink infrastructures. Without cooling solutions, urban centers might become unlivable for the marginalized.

Examples

• Chennai, India, faced drought in 2019 despite having flooded four years earlier due to poor planning.
• In 2003, a European heatwave killed over 70,000 across urban regions.
• Phoenix's urban temperature rises have tripled heat-related deaths over a decade.

5. Heat Drives Migration

As temperatures rise, animals instinctively move toward cooler habitats. Marine species are doing so four times faster than creatures on land. However, migration isn’t as simple for all animals—the melting ice deprives polar bears of hunting grounds, while salmon die in overheated rivers.

Humans face similar challenges. Millions flee droughts, heat, and crop failures, but options are often limited to those with access to resources. This crisis has already begun to reshape global demographics, exacerbating tensions in host nations.

Migration doesn’t come without deadly risks. Unauthorized migrants, largely displaced by climate conditions, face extreme heat in areas like Arizona's Sonoran Desert, where water scarcity can mean life or death.

Examples

• The UN predicts 700+ million climate migrants by 2030, mainly in Asia and Africa.
• Rising temperatures render entire regions, such as parts of the Middle East, unlivable.
• Border Patrol forces use helicopters and heat to deter migrants in Arizona deserts.

6. Heat-Driven Disease Risks

Warmer climates expand the range of heat-loving pathogens and vectors. Mosquitoes like Aedes aegypti thrive in rising temperatures, putting billions at risk of infections like dengue and yellow fever by 2080.

Thawing permafrost could unleash dormant ancient bacteria and viruses, posing unknown threats to human immunity. Changes in animal migration patterns are also increasing mammalian virus transmission risks, heightening the chances of another global pandemic.

Diseases already spreading include malaria via expanding mosquito ranges, and vibrio bacteria invading post-storm US coastal waters.

Examples

• Dengue fever affects over 390 million per year, and mosquito territories are spreading.
• Arctic permafrost releases ancient bacteria into the environment as it thaws.
• Nipah virus outbreaks, with fatality rates up to 75%, are linked to disrupted habitats.

7. Urban Planning Must Change

Urbanization exacerbates vulnerabilities to climate crises. Poorly designed cities fail to manage run-offs or preserve naturally cooling vegetation, leaving poorer demographics at severe risk from heat events.

Improved urban planning is essential to shield cities from future disasters. Strategies include planting more trees and designing smarter water conservation systems. Without these changes, inequality will deepen, dividing populations into those with cooling access and those exposed.

Resilience efforts in cities like Los Angeles and Paris—adding shaded public spaces and innovating cooling systems—hint at possible solutions.

Examples

• Cities like Los Angeles deflect sunlight with reflective buildings to manage urban heat.
• Paris aims to shade streets with increased tree cover to lower local temperatures.
• Chennai’s slums, lacking such investments, bear extreme heat’s heaviest consequences.

8. Economic Consequences of Heat

Extreme heat is not just a climate issue but a massive economic burden. Since the 1990s, heatwaves have cost over $16 trillion in global economic damages, making them deadlier and more expensive than other natural disasters.

Heat disrupts agriculture, productivity, and infrastructure, resulting in job losses, failed harvests, and healthcare burdens. Industries reliant on outdoor labor suffer most, leaving affected communities grappling with poverty cycles.

Comprehensive climate action is not just ethical; it’s financial sense. Adopting renewable energy and cooling infrastructure could save trillions otherwise lost to inaction.

Examples

• In 2019, extreme heat killed more people globally than all other natural disasters combined.
• Droughts exacerbated by warming are crippling crop production in Africa.
• Productivity loss during heatwaves stalls economic growth in urban areas worldwide.

9. There is Still Hope

Despite daunting challenges, Goodell highlights inspiring individuals and communities pushing for sustainable innovations. From activism to science, people around the world refuse to give up hope.

The pandemic taught us how quickly societies adapt under pressure. This same urgency could apply to battling climate change—through collaborative and decisive global action.

It’s up to humanity to decide whether we passively accept worsening conditions or actively build a healthier, more inclusive future.

Examples

• Engineers are innovating cooling technologies for cheaper access worldwide.
• Environmental activists are fighting to protect wetlands and natural cooling systems.
• Community-driven renewable energy projects are gaining traction even in vulnerable areas.

Takeaways

1. Prioritize personal cooling and hydration strategies to survive heatwaves.
2. Support local efforts for urban greening and infrastructural improvements to reduce urban heat islands.
3. Advocate for policies addressing global climate migration and renewable solutions to help vulnerable groups.