As we sweat through the danger season of extreme heat, it’s important to keep in mind three things: Stay Safe. Check in on others to make sure they are safe. Inform yourself about what is causing heat waves and what can be done about it.

Heat waves are the number one weather-related cause of death–greater than hurricanes, floods and tornadoes combined. This summer’s heatwave in Europe caused 1,500 deaths, while NYC suffers over 500 heat-related deaths each year. By 2100, we can expect over 4 million deaths annually due to extreme temperatures. What makes heat waves so deadly? Compared to floods and hurricanes, they occur over large regions, are more intense in cities where most people live, and are often accompanied by high levels of air pollution. Extreme heat can also lead to power outages and transportation delays, which compound the health risks. Perhaps in part because we don’t name heat waves like we do hurricanes, the average person and policy maker may not recognize the dangers of extreme heat, and thus many of us are not prepared.

In the 2021 heat wave in Oregon, Washington and British Columbia, 65 year-old Juliana Leon was one of hundreds of people who died. Her body temperature was 110 degrees when she pulled her car over and rolled down the windows, overwhelmed by the heat. Ms Leon’s daughter has brought a civil suit against fossil fuel companies for their role in creating the extreme weather that led to her mom’s death. And science supports her claims, showing that around the world, climate change has at least doubled the number of extreme heat days.

Anyone can die during extreme heat, but children, pregnant women, and those over 65 are especially at risk. So if you are out and about during extreme heat, especially if the humidity is high, watch out for heat exhaustion symptoms. You may want to have someone accompany you so they can help if you succumb to the heat.

According to the Mayo Clinic, symptoms of heat exhaustion may start suddenly or progress over time, especially with prolonged periods of exercise. Heat exhaustion symptoms include:

If you think you have heat exhaustion, you should:

Heatstroke is more serious because your body is no longer able to cool down on its own. If not treated, heatstroke can quickly damage the brain, heart, kidneys and muscles, and lead to death. Heatstroke symptoms include:

If you or someone you are with has heat stroke symptoms, call 911 immediately.

People who are socially isolated – seniors, homeless, mentally ill, and those with substance abuse disorder – are more likely to die during extreme heat. Most deaths during the Pacific Northwest heat wave occurred in private residences.

Individuals and governments can take action to reduce social isolation. You can call or visit loved ones, and if they don’t have air conditioning, help them move to a cooling center. Cities can engage communities in education and planning for extreme heat and develop early warning systems and coordinated response plans. They can plant trees and gardens to create shade and alleviate higher temperatures caused by urban heat islands. You can also support organizations like the Finger Lakes Climate Fund in upstate New York, which helps low-income residents install heat pumps and insulation to keep their homes cool during extreme heat. Making homes more energy efficient is also a way to reduce carbon emissions, and thus attack the cause of more frequent and severe heat waves.

“The heat is so intense that I cannot continue writing long…It exhausts my Spirits, and takes away all my Strength of Mind and Body. ” John Adams, Philadelphia 1776

It’s true that heat waves have occurred throughout history. The signers of the Declaration of Independence deliberated through stifling heat in Philadelphia’s Independence Hall in 1776. Eyewitness accounts reported that the sweltering temperatures, along with swarms of flies from a nearby stable, contributed to a tense atmosphere and slowed down debate.

But today heat waves occur earlier in the year. They are more frequent. And they last longer.

Thanks to new developments in “Attribution Science,” scientists can now pinpoint with certainty how much a higher than average temperature can be attributed to rising carbon levels in the atmosphere. They have created the Climate Shift Index to show how much climate change influences the temperature on a particular day. For example, a Climate Shift Index of 5 means that a high temperature is occurring 5 times more frequently than it would have occurred in a world without human-caused carbon pollution. These and related scientific advancements have enabled lawsuits against the fossil fuel industry, like the one brought by Ms Leon’s daughter, to have a greater chance of success in court. And soon, according to a recent Harvard Environmental Law Review article entitled Climate Homicide, we may be seeing not just civil suits but also criminal suits against big carbon polluters.

To help reduce the impacts of heat waves, public officials and nonprofit groups can create community interventions that reduce the social isolation of older adults. Citizens can urge elected officials to consider legislation mandating water breaks for outdoor workers, such as the bipartisan Asunción Valdivia Heat Illness, Injury, and Fatality Prevention Act.

In the end, however, no amount of connecting isolated seniors, or providing relief for workers laboring under the hot sun, will be enough to protect us from the dangers of ever more extreme heat. Rather we must attack the problem at its source – rising levels of carbon in the atmosphere. We must urgently reduce carbon emissions now.

To find out if your area is under a heat alert, you can enter your zip code at the Centers for Disease Control and Prevention HeatRisk website. I was able to use the site during the June heatwave over much of the US, although the top of the site states: “This website is no longer being maintained, and no new data will be added.” 

Disclosure: I am a supporter of and have received help for electrifying my home from Finger Lakes Climate Fund.