If there’s one kind of weather extreme that scientists clearly link to climate change, it’s worsening heat waves. In general, climate models indicate that heat waves all over the globe will grow more frequent and more intense as the world warms.
There’s the typical hot summer weather—and then there are heat waves! Much like other natural disasters, heat waves can be very dangerous.
Most of the world’s population has experienced record-breaking heat in recent days. This year, something else is adding fuel to the fire: the El Niño climate pattern. That seasonal shift makes global temperatures warmer, which could make 2023 the hottest year ever recorded.
Heat waves are already the deadliest weather-related disaster in the U.S. Not only do extreme temperatures cause heat exhaustion and severe dehydration, they also raise the risk of having a heart attack or stroke. Those risks are even higher in neighborhoods that are lower-income and communities of color, where research has found temperatures are hotter than in white neighborhoods. However, anyone can suffer from a heat-related illness if they over-exert themselves or simply don’t take extreme heat warnings seriously.
What are heat waves?
A heat wave is a prolonged period of unusually high temperatures for a region. Interestingly, there is no universal definition in terms of “how high.” To be considered a heat wave, the temperatures have to be outside the historical averages for a given area.
That said, we often think of a heat wave typically lasting 2 or 3 (or more) days—and generally 10 degrees or more above average. Heat waves happen when there is trapped air that will feel like the inside of an oven! Usually, the culprit is a high-pressure system that forces air downward.
This force prevents air near the ground from rising. The sinking air acts like a cap. It traps warm ground air in place. Without rising air, there was no rain, and nothing to prevent the hot air from getting hotter.
Heat can kill!
Heat is the number one weather-related killer. Heat kills by pushing the human body beyond its limits. In extreme heat and high humidity, evaporation is slowed and the body must work extra hard to maintain a normal temperature.
Most heat disorders occur because the victim has been overexposed to heat or has over-exercised for his or her age and physical condition. Older adults, young children and those who are sick or overweight are more likely to succumb to extreme heat.
Conditions that can induce heat-related illnesses include stagnant atmospheric conditions and poor air quality. Consequently, people living in urban areas may be at greater risk from the effects of a prolonged heat wave than those living in rural areas. Asphalt and concrete also store heat longer and gradually release heat at night, which can produce higher nighttime temperatures known as the “urban heat island effect.”
While extreme cold is also dangerous, heat waves become life-threatening more quickly if proper precautions are not taken. Heat was responsible for 1,577 deaths in 2021—a 56% increase from 1,012 deaths in 2018.
Preparation and Prevention Tips – Heat wave dangers
- Properly install window air conditioners, sealing any cracks and insulating if necessary
- Check A/C ducts for proper insulation and clean filters
- Install awnings, blinds, or light-colored drapes and keep them closed to keep sunlight and heat out
- Upgrade your windows and weather-strip doors to keep heat out and cool air in
- Make sure your first aid kit is updated and get trained in first aid relief
- Have a plan for wherever you (and your family members/pets) spend time during a heat wave—home, work, and school—and prepare for power outages. Discuss heat safety precautions with members of your household.
- Check the contents of your emergency disaster kit in case a power outage occurs
- Be aware of weather forecasts and the upcoming temperature changes
- It’s not just the high temperature. The heat index is the temperature the body feels when the effects of heat and humidity are combined. See the heat index chart.
- A home generator is the safest and most reliable solution. Power outages are common during heat waves because the need for A/C puts too much pressure on the power grids. A standby generator, however, automatically keeps the A/C running, the lights on, food and medicine from spoiling, and medical devices operating.
During a heat wave remember…
Stay hydrated with plenty of water—even if you’re not thirsty. Hot weather causes you to sweat, and it’s vital to replenish the lost fluids or you’ll overheat. Have a water bottle within reach as you go about your day to avoid dehydration. Try to stay inside during the hottest part of the day (10 A.M. to 4 P.M.) and limit time outside in the sun. Avoid strenuous activity and postpone outdoor games and events.
While it’s tempting, please don’t drink alcohol, sugary soda, coffee, energy drinks, or other caffeinated beverages, as they dehydrate you! That’s the last thing you need during a heat wave. It’s also recommended that you eat small meals and eat more often. Eat food with nutrients (not empty carbs) and also food with higher water content (fruits and vegetables) and wear light, loose-fitting, airy, light-colored clothing and a hat made of breathable material. Tight clothing traps heat.
Heat and sweating also can lower the amount of fluid in the body, which can reduce blood volume and lead to dehydration. This can interfere with the body’s ability to cool off and may create strain on the heart.
When the body loses more fluid than is taken in, the body may not have enough water or other fluids to carry out its normal functions. Anyone can become dehydrated, and it can lead to serious complications for people at greater risk due to age, chronic conditions or outdoor activity like work or exercise.
People with a history of high blood pressure should monitor their blood pressure during heat waves. They also should drink plenty of fluids to stay hydrated, avoid the midday heat, eat a healthy diet, apply sunscreen if outdoors and wear a hat. In most cases, when in doubt, stay inside a cool environment in your home.
Your body isn’t keeping up with the heat if you experience:
- Cold, clammy skin
- Rapid pulse
- Excessive sweating or an inability to sweat
- High body temperature (over 103 degrees) with dry skin (not sweating)
- Muscle cramps or spasms
- Swelling in your arms or legs
If you or a loved one are exhibiting more than one or two of these symptoms, seek medical intervention immediately.
If you feel overheated, cool off with wet washcloths on your wrists and neck, or take a cool sponge bath or shower. Carry a cold water bottle spray or cooling facial mist with you, and spritz cold water on your pressure points to bring your body temperature down.
Keep others safe
During hot weather, check on your neighbors and friends, and be sure someone will check on you, especially if you live alone. Don’t forget about your pets! Keep their water dishes full, keep pets in air-conditioning, and never leave them (or children!) in the hot car. Don’t learn the hard way, some medications can affect your ability to stay hydrated and respond to high temperatures so check with your prescriber if you want to be safe.
During heat waves, tune in to a NOAA radio station and listen for weather updates from the National Weather Service (NWS).
Too hot at the house? Go to the library or a designated public shelter if your home loses power during periods of extreme heat. Text SHELTER + your ZIP code to 43362 (4FEMA) to find the nearest shelter in your area (example: shelter 12345).
We hope these tips are helpful during the next heat wave. Print out this list and place it with your First Aid Kit so you’re better prepared when the next heat wave hits.