Jeff Goodell The Heat Will Kill You First: Life and Death on a Scorched Planet Little Brown and Company, 2023, 400 p., $29.00

In 2023, the Earth experienced unprecedented high temperatures and endured the hottest summer documented since 1880. The extreme temperatures coincided with the publication of Jeff Goodell's The Heat Will Kill You First: Life and Death on a Scorched Planet. The book is essential and accessible reading on the dangers presented by heat for human populations, a guide to the actions needed to reduce these risks, and an inspiration for further research into the implications of global warming.

Goodell is a renowned climate journalist who has written extensively on the topic of climate change, including earlier books on the coal mining industry, climate mitigation, geoengineering, and rising sea levels. In The Heat Will Kill You First, Goodell turns his attention to heat waves, aiming to “convince you to think about heat in a different way” (p. 19). Goodell begins by describing how heat is “invisible” compared with other environmental disasters such as floods, hurricanes, and earthquakes. Those events are sudden and traumatizing and leave a durable mark on the territory and community. While other natural disasters are given names—to support documentation, social memory, and record-keeping—heat waves are unnamed and are sometimes even seen positively, as holiday weather. Despite its relative invisibility compared with other disasters, heat is responsible for the highest yearly death toll attributable to an environmental disaster in some countries. The human thermoregulatory system can fail when exposed to high temperatures for a prolonged time, leading to hyperthermia, heatstroke, and death. Through multiple real-life examples, Goodell shows how heat is a pervasive force that infiltrates homes, exploits vulnerabilities, and proves especially detrimental for those unable to shield themselves.

Goodell pays particular attention to how the impact of heat waves exacerbates social inequalities. For instance, the coexistence of medical conditions such as cardiorespiratory disease or diabetes reduces peoples’ ability to thermoregulate during heat waves. The prevalence of such conditions is a major factor explaining the higher death toll caused by extreme heat in older adults. Goodell shows that age is not the only factor determining increased health risks during a heat wave. For people at younger ages, heat waves remain a major health threat, in particular for those who downplay its risks and do not take precautions, and for those who cannot afford air conditioning or insulation. Socioeconomic status and employment conditions affect the risks posed to individuals by a heat wave. For example, Goodell describes the high exposure of agricultural workers to heat waves and the necessity of adaptation measures to avoid fatalities. Such measures vary in their accessibility or availability creating inequalities in this sector.

Goodell dedicates ample space to the subject of adaptation to heat and the limits of such measures. One informative chapter revolves around the invention and widespread adoption of air conditioning, especially in the United States. Air conditioning provides relief from scorching temperatures to individuals who can afford it, which potentially amplifies inequalities in health and mortality in warmer regions. Furthermore, air conditioning is not a complete solution. During prolonged heat spells and widespread use of air conditioning, electric grid lines are put under high stress and in case of failure could paralyze entire cities.

Other adaptive measures Goodell discusses in the book relate to the challenges faced by cities in an ever more urbanized and hotter world. The formation of urban heat islands puts cities at risk, exacerbating urban–rural inequalities in health. Urban heat islands result from reduced heat release in cities due to factors like limited vegetation, nonreflective surfaces, urban canyon effects, and human activities, making them warmer than rural areas that host more green spaces and water bodies. Some of the solutions discussed in the book relate to urban greening and white rooftop painting but Goodell describes how these innovations face several hurdles. Urban greening could be effective in providing shade and reducing heat islands but challenging in dry and hot regions with limited access to water. Roof painting may not be suitable in historical centers where architectural features of buildings cannot be changed easily.

Migration patterns, too, are heavily influenced by temperature anomalies. Goodell describes a paradoxical phenomenon relating to the increased internal migration in the United States of individuals into areas classified as having a higher climatic risk. In particular, several areas in the South that are badly affected by heat waves and sea level rise experience larger population growth as people retire to warmer climes. The combination of rising population and escalating climatic risks may pose significant challenges for these areas in the future. Conversely, for the economically disadvantaged who increasingly suffer the consequences of climate change, migration is often the ultimate solution to escape inhospitable climatic conditions that render certain economic activities such as agriculture unfeasible. At the same time, migratory paths are becoming increasingly perilous and impractical due to worsening weather conditions.

Goodell's book covers three principal themes relating to heat and humanity that have been of particular concern for population scholars: the increasing prevalence of heat waves and their broad impacts on population outcomes; the importance and complexity of adaptation measures; and the amplification of existing sociodemographic inequalities due to climate-induced challenges. In recent years, academic research on the implications of heat waves has intensified. A recent study marked the catastrophic European heat wave of 2003, responsible for approximately 70,000 deaths, as a significant inflection point leading to an increase in studies on temperature-related mortality and morbidity (Campbell et al., 2018). In 2022, heat waves determined about 60,000 deaths in Europe indicating that the impact of heat waves remains deadly, raising concerns about the ability of individuals to adapt to rising temperatures (Ballester et al., 2023). The increasing prevalence of heat waves makes studies on the population implications of climate change particularly pressing.

Goodell provides novel perspectives to population scholars, delving into relatively unexplored topics in existing demographic research. He highlights how climate change can create environments that favor the spread of disease vectors, such as mosquitoes and ticks. This may result in a wider distribution of diseases like dengue, Lyme disease, and malaria, determining new challenges to public health and human mortality. Additionally, an important area of research highlighted in the book is climate change attribution which seeks to understand whether specific environmental disasters arise from natural climatic variations or are determined by human activities and greenhouse gas emissions. More research is needed on this topic, to complement existing studies calculating the mortality cost of carbon (number of deaths caused by CO₂ emissions) (Bressler, 2021) and estimating the burden of heat-related mortality determined by human-led climate change (Vicedo-Cabrera et al., 2021). Further studies on the demographic and health cost of anthropogenic climate change are essential as well as on the potential of mitigation to limit such impacts.

While Goodell's book discusses the effects of heat on migration, mortality, and morbidity, it does not delve so deeply into its impact on fertility, perinatal, and maternal health. Compared with mortality, research on the impact of heat on such outcomes has been more limited. Despite some recent interest in the impact of heat on fertility and birth outcomes, there remain many unresolved questions on this topic (Barreca et al., 2018; Chersich et al., 2020; Hajdu & Hajdu, 2022). The mechanisms linking temperature with fertility are still debated and are critical to comprehending how heat shapes reproductive health and behavior in a world with low fertility rates and an aging population. The book could also have delved deeper into the compounding impact on public health and demographic dynamics when multiple environmental disasters simultaneously impact a population. Such compound effects are especially pronounced in regions where heat waves occur simultaneously with wildfires or flooding events, potentially amplifying the impact on public health outcomes.

This public science book reads effortlessly and is written in a journalistic style, combining scientific evidence with the lived experiences of individuals suffering the negative consequences of heat. Each chapter reads as a standalone story that covers in depth how heat affects a particular aspect of life, ranging from agricultural work and the spread of vector-borne diseases to survival in boiling cities and the invention of air conditioning, making the text an easy reference volume. Consequently, it offers an insightful read both for the general public and the expert reader, underlining the pressing challenges determined by heat for human life on Earth. As reflected in the book's provoking title, the pervasive effects of heat will inevitably touch us all, compelling us to grapple with its implications.