What Is a Heat Wave and Why Are They More Common?

Essential Tips for Coping Without Air Conditioning During a Heat Spell

The start of summer was greeted by a scorching heat wave that blanketed a large swath of the country. With another hot summer predicted, it could be the first of many, experts warn.

Frequent heat waves have become the norm for millions of Americans each summer, leading to broken air conditioners, severe comfort issues, and heat-related illnesses.

HVAC.com explains what a heat wave is and why they are occurring more frequently. We will also discuss tips for staying safe during extended heat waves and highlight the critical role a properly functioning air conditioning system plays when temperatures and humidity levels soar.

Understanding Heat Waves and Their Risks

The definition of a heat wave can vary slightly, as there is no universal temperature threshold. However, a heat wave generally refers to a prolonged period of excessively hot weather, often accompanied by high humidity. Such weather conditions are characterized by temperatures significantly above the average for a specific region during that time of year.

Heat wave temperatures pose serious health risks, particularly to vulnerable populations such as the elderly and young children, underscoring the importance of staying informed and taking precautions during these periods. Common medical issues include heat exhaustion, heatstroke, and exacerbation of underlying medical conditions.

“If you’ve been out in the sun, drink plenty of liquids and find a cool place that will help lower your body temperature,” said Dr. Jay Woody, chief medical officer of Intuitive Health and a co-founder of Legacy ER & Urgent Care. "In that case, you need to alleviate the source of heat directly causing the dehydration. A cool shower can also help reduce the body’s temperature. If symptoms of heat exhaustion persist, such as dizziness, sweating, high body temperature, confusion, vomiting, seizures, unconsciousness, or difficulty breathing, seeking medical attention is extremely important.”

Heat Wave Forecast for 2024

According to the National Oceanic and Atmospheric Administration’s Climate.gov site, 2023 was the warmest year on record and featured several noteworthy heat waves. The 10 warmest years have all occurred within the past decade. 

Unfortunately, relief isn’t in sight. According to the Weather Channel, this summer – which officially started on June 20 – is expected to be “one of the hottest on record,” with the Southwest, Plains, Midwest, and East Coast expected to receive the brunt of the heat through September. Areas of the West Coast might be an exception from extreme heat.

“We’ve run out of superlatives to describe what we expect as an historic summer,” Todd Crawford, Vice President of Meteorology, Atmospheric G2, said in a Weather Channel article.

Previous record highs fell like dominos during a heat wave in mid-June. On June 17, a Chicago heat wave pushed temperatures to 97 degrees, breaking the old record of 96 degrees from 1957. During the same week, in New York, Governor Kathy Hochul activated the state’s Emergency Operations Center in response to the heat wave, a day after Syracuse, NY, set a record high of 94 degrees.
“This is a deadly event,” Hochul said in a new release on June 17. “We have seen blizzards, we have seen flooding, we had hurricanes, we had tornadoes. But this heat event is most likely to cause more deaths.”

According to a CNN report on June 19, emergency room visits for heat-related illnesses were 215% higher on June 17 in the state of New York compared to an average day in June.

Why Are Heat Waves Occurring More Frequently?

From the Southwest to the Northeast – and everywhere in between – heat waves have become a part of everyday life for many Americans during the summer months, as has sunscreen, air conditioning, and trips to the pool.

Heat waves are occurring more frequently due to a combination of factors including climate change, which is leading to overall warmer temperatures globally. Urbanization and the “heat island” effect exacerbate this by trapping heat in densely populated areas, according to the U.S. Environmental Protection Agency. Changes in weather patterns and atmospheric circulation also play a role in the increased frequency and intensity of heat waves observed in recent years.

The Role Air Conditioning Plays During a Heat Wave

When temperatures surpass 90 degrees and even triple digits, air conditioning becomes a necessity to prevent heat-related illness.

If You Have Air Conditioning:

If you have a cooling system – whether it’s a window unit, central air conditioner, mini-split, or heat pump – make sure it’s working properly. If it hasn’t received maintenance this year, consider contacting an HVAC contractor to inspect the system.

They can clean, calibrate, and adjust any necessary components to ensure your AC is working properly and ready to handle an upcoming heat wave. An HVAC professional can also uncover any minor issues and recommend the needed repairs before they become a more serious issue down the road.

Check your HVAC system’s air filter before a heat wave arrives. If it’s clogged or dirty, change it. A clogged filter restricts airflow to the system, causing it to strain to reach the desired temperature, potentially causing a complete shutdown.

If You Don’t Have Air Conditioning:

If the temperature inside your home is approaching or exceeds 90 degrees, it can pose a danger to you, your family members, and pets. If you don’t have air conditioning or the system isn’t working properly, go to a local cooling center for a few hours in the afternoon when the outside temperature is the hottest.

Click here for information about cooling centers in your area, or contact your local health department. Public places such as museums, libraries, swimming pools, or movie theaters are also ideal locations to find relief from the heat.

You can also use fans to keep cool during the summer months, but they should not be relied on during extreme heat waves, as they will not provide adequate cooling.

What Happens When Your AC Fails During a Heat Wave?

If you have an air conditioner that breaks down during a heat wave, contact an HVAC contractor immediately. They can make any necessary repairs or install a new system to ensure your home returns to a comfortable temperature quickly.

You may need to contact a few highly reputable HVAC companies, especially during heat waves when they tend to be busiest and may have scheduling delays of a few days. This ensures you have options and can potentially get your AC fixed sooner.

While you wait for your system to be repaired or replaced, consider temporarily relocating to a cooler location, such as a friend’s or family member’s home, or a public place with air conditioning, especially if temperature indoors becomes dangerously high.

How to Keep Pets Safe During a Heat Wave

Don’t forget about your furry friends during heat waves. Ensure your pets have access to cool, shaded areas indoors. Provide ample fresh water and avoid exercising them during peak temperatures. Monitor your pets closely for signs of overheating, such as excessive panting or lethargy, and take immediate steps to cool them down if needed.

Never leave a dog in a car during a heat wave, even for a short period. Temperatures inside a parked car can rise to dangerous levels quickly, leading to heatstroke and potentially fatal consequences for your pet.

Take Appropriate Precautions During Heat Waves

Heat waves can quickly lead to life-threatening health conditions including heat exhaustion and heatstroke if not addressed promptly. It’s crucial to stay cool and hydrated during these extreme conditions. Remember to use air conditioning, drink plenty of water, and consider visiting cooling centers, pools, or other air-conditioned spaces to stay safe and comfortable.

“As much as it’s fun to take a swim, go to the water park or ride our bikes, if we’re not replenishing liquids, our bodies cannot regulate their temperature, ultimately leading to adverse side effects,” Woody said. "It’s crucial to take breaks from exposure to heat and keep hydrated by drinking plenty of water.”