The Heat Will Kill You First: Life and Death on a Scorched Planet

In 2013, an unusual marine heat wave known as “the Blob” emerged in the northern Pacific Ocean due to a persistent high-pressure system that calmed winds and waves, allowing solar heat to accumulate and raise sea temperatures significantly over a vast area. This warming disrupted the marine ecosystem by killing phytoplankton, the base of the oceanic food web, leading to starvation among krill and other small organisms. The effects cascaded up the food chain, resulting in declines in fish populations, mass strandings of marine mammals, and the largest recorded die-off of seabirds. The Blob also influenced weather patterns on land, contributing to drought conditions and potentially intensifying wildfires along the Pacific coast by preventing nighttime cooling.

The ocean, covering over 70% of the Earth’s surface, helps regulate the planet’s climate by absorbing excess heat from greenhouse gas emissions. However, as the ocean warms, it alters currents, weather patterns, and the distribution of marine life. Warming waters cause thermal expansion, contributing to sea-level rise, and disrupt habitats, leading to migrations of species toward cooler regions.

Marine heat waves like the Blob are becoming more frequent and severe due to climate change, causing widespread ecological damage. For instance, the kelp forests of Monterey Bay in California, once thriving ecosystems rich in biodiversity, have been decimated. Warmer waters led to the outbreak of sea star wasting disease, eliminating key predators of purple sea urchins. The unchecked urchin population then overgrazed the kelp, causing the collapse of these underwater forests. Similar events are occurring globally, with marine heat waves leading to mass die-offs of marine organisms, shifts in species distributions, and declines in biodiversity.

Coral reefs are particularly vulnerable to rising ocean temperatures. Even slight increases can disrupt the symbiotic relationship between corals and the microscopic algae that provide them with most of their energy, leading to coral bleaching and death. The Great Barrier Reef has suffered multiple bleaching events, affecting its health and the economies dependent on it. Scientists are exploring ways to enhance coral resilience, such as developing heat-tolerant strains or using probiotics, but these interventions may not be sufficient to counteract the rapid environmental changes.

In June 2021, during an unprecedented heat wave in the Pacific Northwest, Sebastian Perez, a 38-year-old migrant worker from Guatemala, died from heat exposure while working at Ernst Nursery & Farms in Oregon’s Willamette Valley. Having recently arrived in the United States to earn money to build a house and support his wife, Maria, Perez labored in extreme conditions, moving heavy irrigation pipes without adequate breaks, shade, or access to cool water. Temperatures soared above 100 degrees Fahrenheit, peaking at 106 degrees on the day he collapsed. Despite experiencing signs of heat stress, he continued working until he ultimately succumbed to the heat.

Millions of workers in the United States face hazardous heat conditions, yet there are no federal regulations specifically addressing heat exposure in the workplace. Farmworkers are especially vulnerable, being significantly more likely to die from heat-related causes than workers in other sectors. Efforts to implement protective legislation have been minimal, with only a few states, such as California and Washington, enacting heat-related workplace safety rules at the time of Perez’s death. In Oregon, despite long-standing advocacy, meaningful regulations were not in place, leaving workers unprotected during extreme heat events.

Historically, racial assumptions about heat tolerance were used to justify harsh labor conditions for enslaved African Americans and later for migrant workers. In the 18th and 19th centuries, the belief that people of color were naturally suited to endure extreme heat was widespread, particularly in the American South. This pseudoscientific ideology provided moral justification for slavery, allowing enslavers to subject enslaved individuals to brutal working conditions in scorching fields. Figures like Samuel Cartwright, a Louisiana physician and racial theorist, argued that African Americans operated under “physiological laws” that actually made laboring in the sun beneficial for them. These racist beliefs persisted into the 20th century, influencing employment practices in which immigrants and people of color were funneled into the most grueling and hottest jobs with minimal safety provisions. During labor shortages in World War I, immigrants from Mexico and Central America were assigned to the hottest operations in industrial centers like foundries and steel mills based on the assumption that they could withstand high temperatures better than white workers. These ideologies supported discriminatory labor practices and still influence how workers are perceived and treated, contributing to systemic neglect of their safety in extreme heat conditions.

Employer negligence further increases the dangers faced by vulnerable workers. Ernst Nursery & Farms, where Perez worked, had a history of safety violations, including failures to provide water and post essential health information. The use of independent labor contractors allows companies to distance themselves from responsibility for worker welfare, making it difficult for employees to advocate for safer conditions or even know who is accountable. Workers often lack basic protections like shade, adequate rest breaks, and access to cool water—simple measures that can prevent heat-related illnesses and deaths.