The Climate is Heating Up, and So Are Our Bodies

Summer is nearing an end in the Northern Hemisphere, and it’s been one of record heat in many places. We should now be long past 'just' being warned of the impending impacts of climate change – around the world people live every day with increasingly severe effects of a warming planet. We need to know how to try and adapt to it; the consequences of ignoring what is happening will only hurt us.

When it comes to human health, the impacts of a changing climate can be devastating.

This year the news has been full of stories about the threats posed to human health by extreme heat. Often called a “silent killer”, extreme heat ranks as the most lethal weather-related disaster in the U.S., and deaths are increasing.  

Extreme heat is breaking records around the world, with wildfires and poor air quality compounding the crisis, according to a report from the World Meteorological Organization

Per the U.S. National Weather Service, heat is the leading weather-related killer in the United States, resulting in hundreds of fatalities each year. Heat can be very taxing on the body and can lead to heat related illnesses or make existing health conditions worse. 

According to the World Health Organization, heat stress is the leading cause of weather-related deaths and can exacerbate underlying illnesses including cardiovascular disease, diabetes, mental health, asthma, and can increase the risk of accidents and transmission of some infectious diseases. Heatstroke is a medical emergency with a high-case fatality rate.

Let’s take a closer look at Maricopa County in Arizona, which is one of the fastest growing counties in the state. Through the first half of the month of August, more than 400 people are believed to have died from extreme heat, according to official figures.

From The Guardian:

Heat-related deaths have soared in Maricopa county over the past decade, with 645 in 2023 compared to 61 in 2014. The county has become increasingly unlivable for many amid record-breaking heatwaves driven by the global climate crisis, unchecked urban sprawl and an affordable housing crisis – which combined with patchy mental health and substance misuse services has contributed to a growing unsheltered population.

Here are a few statistics listed on the government website for Maricopa County:

·       The nation’s 4th largest county in terms of population;

·       2022 population of 4.5 million people, according to U.S. Census Bureau;

·       Makes up more than half of Arizona’s population.

Extreme heat is also an equity issue, especially regarding access to air conditioning.

Journalist and author Jeff Goodell calls this “the cooled and the cooked” - the cooled are those who spend most of their days in air-conditioning; the cooked are those who must work outdoors in increasingly inhumane temperatures.

Be grateful if you can’t imagine what it’s like to work outside in Phoenix (Maricopa County), for instance, where the five hottest summers have all occurred since 2015. Summer 2025 saw 84 days at or above 100 degrees and 37 at or above 110. The summer of 2024 had more triple-digit days, with 92 days at 100 degrees or higher and 54 days at or above 110. 

Goodell’s summation of this predicament of those on the ‘frontlines’ of extreme heat and those who are not applies to the U.S. and the world:

The faster our world heats up, the faster the divide between the cooled and the cooked will widen,” Goodell argues. “Ultimately, it is symptomatic of the larger injustice of the climate crisis, which is that the people who have done the least to cause it are the ones who will suffer the most from its impacts.

The world needs to heed this message, and soon.  We can't keep kicking the can down to road.