Because of climate change, last summer was the hottest ever recorded on Earth. The record may continue to be broken: Extreme heat is expected to become even more frequent.
The scorching heat has led to an increase in heat-related deaths in the United States, according to the Department of Health and Human Services, with approximately 2,300 deaths in the summer of 2023. Extreme heat, defined as a period of two to three days with high heat and humidity with temperatures above 90 degrees Fahrenheit, can have serious health consequences, including symptoms like headache, dizziness, loss of consciousness, nausea, and confusion.
As we face more extreme heat, you may be wondering how you can protect yourself and your loved ones. Read on to learn about heat-related illness, who’s most at risk, and more.
What happens when our bodies are exposed to extreme heat?
As our body temperature rises, our bodies attempt to cool down by opening up more blood vessels near the skin to begin sweating. The evaporation of our sweat regulates our body temperature, but it also leads to losing fluids and minerals.
When it’s too humid, sweating alone doesn’t do the trick. The heart must work harder to bring blood around the body. It starts beating faster, which can cause light-headedness, nausea, and headache.
This process can affect our health in different ways, including increasing our risk of hospitalization for heart disease, worsening asthma, and injuring kidneys due to dehydration. It can also result in heat-related illness. Below are some effects of heat on our bodies:
- Heat cramps: Occur when a person loses salt through sweating, which causes painful cramps. Symptoms begin as painful spasms after heavy sweating, usually in the legs or the stomach. Heat cramps can lead to heat exhaustion or heat stroke.
- Heat exhaustion: This occurs when the body loses an excessive amount of water and salt, usually during intense physical activity. Symptoms include irritability, heavy sweating, and weakness, including muscle cramps. Heat exhaustion can lead to heat stroke.
- Heat stroke: This is the most severe heat-related illness. It happens when the body can’t cool down and reaches a temperature of 106 Fahrenheit or higher within 10 to 15 minutes. If the person doesn’t receive emergency treatment, it can cause permanent disability or death. Symptoms include confusion, loss of consciousness, and seizures.
What should I do if someone experiences a heat-related illness?
If you or someone you’re with begins to show signs of heat illness, the Centers for Disease Control and Prevention recommends the following:
- Heat cramps: Stop all physical activity, drink water or a sports drink, move to a cool place, and wait for cramps to go away before resuming activity. If the cramps last more than an hour, you’re on a low-sodium diet, or you have heart problems, get medical help.
- Heat exhaustion: Move the person to a cool place, loosen their clothes, use a cool bath or cloths to try to lower their body temperature, and give them a sip of water. If the person throws up, or if their symptoms last longer than an hour or worsen, get medical help.
- Heat stroke: Call 911 immediately. Then, move the person to a cooler place, use cool cloths or a cool bath to help lower their temperature, and don’t give them anything to drink.
Read more about heat-related illness and what to do in each case.
Who’s more vulnerable to extreme heat?
While everyone can be affected by extreme heat, some people are more at risk, including people of color.
A 2023 KFF report outlined that because of historical residential segregation in the U.S. (known as “redlining”), people of color are more likely to live in areas that experience higher temperatures from rooftops, asphalt, and sidewalks that retain the sun’s heat (known as the “urban heat island effect”). Additionally, communities of color are more likely to live in areas with fewer trees, which act as a canopy and provide shade, making the heat worse and more direct.
Children under 5, adults 65 or over, and pregnant people are also more vulnerable to extreme heat. If you have a chronic health condition like diabetes, heart problems, or a mental health condition, you’re also at higher risk. (Some psychiatric medications, like antidepressants, can also make people more susceptible to heat).
Lastly, anyone exposed to the sun and extreme heat for long periods is also at higher risk. This includes athletes, people who work outdoors, and unhoused people.
What can I do to prevent heat-related illness during a heat wave?
During a heat wave, follow these tips to stay cool and protect yourself from heat-related illness:
- Never leave your pets or children inside a car.
- Wear loose, light-colored clothing (dark colors absorb more heat).
- Find shade if you’re outside.
- If you don’t have air conditioning in your home, go to a place where you can cool down, such as a local library, community center, local pool or splash pad, or mall. Check to see if your city has designated cooling centers. (Cities like New York have a list of places.)
- Wear a hat.
- Drink (non-alcoholic) fluids often to stay hydrated—and if you have pets, give them water frequently as well.
- Check on your family members or older neighbors who may be more sensitive to extreme heat.
- Avoid using your stove or oven too often or during the hottest parts of the day.
- Cover your windows with shades to keep the heat out.
What are some resources to prevent heat-related illness?
If you need financial assistance to cool down your home, such as to purchase an air conditioner, apply to the federal government’s Low Income Home Energy Assistance Program.
Before you head outside during a heat wave, use the CDC’s HeatRisk tool: Enter your zip code to find the current heat risk in your area and get tips on what to do to stay safe with each risk level.
During a heat wave, also look for a cooling center in your state using the National Center for Healthy Housing’s list.
Check out the National Weather Service’s for more tips and resources.
For more information, talk to your health care provider.