If you’ve stepped outside lately, you’ve likely noticed that after a slow start here in the Northeast, summer is starting to sizzle across the U.S (and the Northern Hemisphere). The Pacific Northwest experienced an unprecedented “heat dome” in May, Canada has gotten so hot that it’s literally on fire, and currently the Southwest has been baking in the triple-digits going on several weeks now. Europe and Asia have also been dealt significant heat waves this year, with parts of China reaching triple digits for weeks on end early this season. The seven (7) hottest days on earth in the past 100,000+ years were all in July 2023!
Learn More about Extreme Heat
Skip to a specific section below:
- A Climate Emergency
- Health Impacts of Extreme Heat
- Heat-Related Disease & Death
- Extreme Heat & Medications
- Climate Change & Extreme Heat Resources
A Climate Emergency
According to IPCC Sixth Assessment Report, in the last 170 years, humans have caused the global temperature to increase to the highest level in the last 2,000 years. The current multi-century period is the warmest in the past 100,000 years. The temperature in the years 2011-2020 was 1.09°C higher than in 1859-1890 (pre-industrial baseline). The temperature on land rose by 1.59°C while over the ocean it rose only by 0.88°C. Since 1950, the number of cold days and nights has decreased, and the number of warm days and nights has increased.
Between climate change fueled extreme weather and a shift into an El Niño climate pattern, 2023 is already breking records and could quite possibly cause the earth to breach the 1.5°C target that was set for in the Paris Agreement. In May 2023, the World Meteorological Organization (WMO) announced that there is a 66% chance that the earth will breach the target in the next five years.
A Crisis of the Extremes
Many people think climate change simply mainly means warmer temperatures. But temperature rise is only the beginning of the story. Because the Earth is a system, where everything is connected, changes in one area can influence changes in all others.
Climate change is causing the weather around the world to get more extreme, and scientists are increasingly able to pinpoint exactly how the weather is changing as the Earth heats up.
Higher temperatures mean warmer and more volatile seas, which lead to higher sea levels and more moisture evaporating into the atmosphere. The more moisture in the air, along with more volatile seas, leads to more intense and extreme storms.
In areas prone to drought, higher temperatures means more moisture evaporating from the land (leading to lakes, rivers, and streams drying up). Less precipitation on these areas leads to drought, which in turn cascades into risks for wildfires and ecosystem destruction.
Health Impacts of Extreme Heat
As climate change worsens, more frequent and longer-lasting extreme heat waves will increase people’s vulnerability to heat-related health impacts; especially among the elderly, the very young, the impoverished, and those living with chronic illnesses.
The Low Down on Low Temperatures
One of the biggest drivers of heat-related health impacts is not the high temperatures, but rather the low temperatures. When temperatures drop at night, it allows our bodies and our environment to cool off and recover from the day’s intensity. With the most recent heat waves, the low temperatures are not dropping like they would in decades past, leading to people being unable to sufficiently cool their homes and their bodies, especially in regions and among populations that lack air conditioning.
“Urban Heat islands”
In cities such as New York, “urban heat islands” (where heat is trapped at the surface due to population and infrastructure density) make surface temperatures between 2-5°F warmer than the less urban areas around them. This is especially concerning for the poor, the elderly, and the homeless.
Heat-Related Death & Disease
Heat-related deaths usually result from heat stroke and related conditions, but also from cardiovascular disease, respiratory disease, and cerebrovascular disease. Heat waves are also associated with increased hospital admissions for cardiovascular, kidney, and respiratory disorders.
Pollution & Air Quality
Heat waves often lead to poor air quality. The extreme heat and stagnant air during a heat wave increases the amount of ozone pollution and particulate pollution. Drought conditions can also occur during a heat wave, meaning that soils are very dry. Drought conditions on top of heat waves can also increase the risk and spread of wildfire, that in turn increases the particulate air pollution. Exposure to air pollution can affect everyone’s health. When we breathe in air pollutants, they can enter our bloodstream and contribute to coughing or itchy eyes and cause or worsen many respiratory and lung diseases (eg. asthma, COPD, and lung cancers), leading to hospitalizations, or even premature death.
Extreme Heat and Medications
Some commonly prescribed and over-the-counter drugs and medications can increase sensitivity to heat and sun exposure.
Photosensitivity
Some medicines contain ingredients that may cause photosensitivity — a chemically induced change in the skin. Photosensitivity makes a person sensitive to sunlight and can cause sunburn-like symptoms, a rash or other unwanted side effects. Below are the types of medications that can potentially cause photosensitivity:
- Antibiotics
- Antifungals
- Antihistamines
- Cholesterol lowering drugs
- Diuretics
- Non-steroidal anti-inflammatory drugs
- Oral contraceptives and estrogens
- Phenothiazines
- Psoralens
- Retinoids
- Sulfonamides
- Sulfonylureas for type 2 diabetes
- Alpha-hydroxy acids in cosmetics
Thermoregulation
Other medications can directly interact with internal body regulation, such as decreasing the amount of sweat produced or the amount of fluids in the body, disrupting blood flow to the skin, and disrupting the hypothalamus. These can all potentially cause heat intolerance or overheating. Additionally, some of these same medications can also cause decreased thirst, which can increase the risk of dehydration in extreme heat. The main classes of drugs that disrupt thermoregulation are:
- Antihistamines and Decongestants
- Beta-Blockers
- Diuretics
- Psychotropic and psychiatric medications
Climate Change & Extreme Heat Resources
Data and Trackers
Heat & Health Tracker – The CDC’s Heat & Health Tracker provides local heat and health information so communities can better prepare for and respond to extreme heat events. Use the search on the right to explore how extreme heat affects your county, populations who are at risk, and response resources.
AirNow – AirNow reports air quality using the official U.S. Air Quality Index (AQI), a color-coded index designed to communicate whether air quality is healthy or unhealthy for you. When you know the AQI in your area, you can take steps to protect your health.
CDC National Environmental Public Health Tracking Network — At the local, state, and national levels, the Tracking Program uses a network of people and information systems to deliver a core set of health, exposure, and hazards data, information summaries, and tools to enable analysis, visualization and reporting of insights drawn from data.
Be Ready, Be Safe
Extreme Heat — Ready.gov is a National public service campaign designed to educate and empower the American people to prepare for, respond to and mitigate emergencies, including natural and man-made disasters. The goal of the campaign is to promote preparedness through public involvement.
Extreme Heat Safety — Learn how to stay safe during a heat wave and how to treat heat-related illness like heat exhaustion from the American Red Cross.
Tips for Preventing Heat-Related Illness – Tips from the National Center for Environmental Health; stay cool, stay hydrated, stay informed.
Protecting Vulnerable Groups from Extreme Heat — Information and resources for specific populations that are disproportionately affected by extreme heat: older adults, infants and children, chronically ill, low income, athletes, and outdoor workers.
Heat Safety Tips and Resources — The National Weather Service Safety Information page is designed to prepare you for excessive heat events, describe what to do during a an excessive heat wave, and inform you about the health dangers of heat. You also will find educational materials and fun games and activities to help educate children about the dangers of heat.
For even more news, information, resources, and policy on climate change, the climate crisis, and the intersectionality of health, climate, and humanity, take a look at our Climate Crisis LibGuide.
