Kevin Miller is pushing the boundaries of heat research. In his lab, he can bring a human participant to the edge of heat exhaustion in just 30 minutes. He uses a treadmill in a chamber heated to nearly 100 degrees. By alternating between walking and sprinting, participants rapidly increase their heart rate and breathing. This might sound extreme, but it’s all part of understanding how our bodies react to heat and finding ways to help during emergencies.
Heat is not just uncomfortable; it’s deadly. In fact, it’s the leading weather-related cause of death worldwide. Miller’s work at Texas State University involves innovative cooling methods, like using ice-filled body bags. This quick cooling technique is inexpensive and could save lives in emergencies.
But the dangers of heat go beyond immediate health risks. Prolonged exposure to high temperatures can damage our overall health, impacting everything from our skin to our DNA. As the planet warms, more people are facing health issues linked to extreme heat.
At the beginning of summer, around 255 million Americans were living in areas with life-threatening heat levels. Unfortunately, many people don’t recognize the signs of heat-related illnesses, which include heat cramps, heat exhaustion, and heat stroke—the last of which can be fatal. Miller explains that when a person’s core temperature hits 105 degrees, their cells can start breaking down, which may lead to organ failure and death.
In stressful heat conditions, mental acuity also drops. Dr. Lisa Patel, a pediatrician with the Medical Society Consortium on Climate & Health, notes that as dehydration sets in, it can feel as if you’re under the influence of alcohol—leading to poor decision-making. Symptoms of heat stroke include confusion, headaches, and loss of consciousness, which all signal a medical emergency.
Research shows that heat affects our brains, too. A study published last year found that high temperatures hinder cognitive functions such as problem-solving and memory. During heat waves, visits to emergency rooms for mental health crises often surge. For instance, researchers at Yale identified that heat could contribute to an estimated 150 additional drug overdose deaths annually in the U.S.
Children and the elderly are particularly vulnerable. A recent report from Save the Children revealed that one-third of the world’s children are exposed to extreme heat—twice the number from the previous year. Children’s bodies are less efficient at regulating temperature, putting them at greater risk. In a specific case, a teenager working outdoors in California’s 108-degree heat was hospitalized for rhabdomyolysis, a condition caused by severe dehydration and muscle breakdown due to heat stress.
Climate change is worsening these health risks. It exacerbates conditions that lead to heat illnesses and mental health crises. Recent studies suggest that prolonged heat exposure could speed up aging on a cellular level. Residents in hotter cities, like Phoenix, may face up to 14 months of biological aging compared to those in cooler areas like Seattle. This has serious implications for overall health and longevity.
To protect against heat, experts recommend several strategies. Dr. Rose Jones advises communities to clarify hydration messaging—water is best, while alcohol and sugary drinks can worsen dehydration. Additionally, wearing broad-brimmed hats and light, loose clothing helps shield against the sun. For outdoor workers, gradually increasing heat exposure can build tolerance and reduce risks.
In clinics, healthcare workers are seeing more patients affected by the heat. Clinics like Snake River Community Clinic in Idaho stock hydration supplies to help those most at risk. Community-based responses are crucial for those without access to air conditioning or other cooling options. However, many face barriers due to financial strain and lack of resources.
As extreme heat becomes a more common threat, it is vital for public health messaging to improve. Recommendations must be clear, accessible, and grounded in the realities those most affected are facing. With climate change, the interplay of heat, air quality, and public health will continue to influence our lives. We must prioritize awareness and preparation to navigate these challenges effectively.
