How To Prevent Heat-Related Illness

Woman drinking water is illuminated by the sun behind her

Carles Navarro Parcerisas / Getty Images

Key Takeaways

  • Heat domes occur when the atmosphere traps hot ocean air, causing temperatures to soar.
  • Heat stress can be a byproduct of excess heat exposure, resulting in heat rashes, fainting, heat exhaustion, and heat stroke. The most vulnerable groups include children, the elderly, and people who cannot afford air conditioning. 
  • Experts recommend avoiding sun exposure and exercise during peak temperature hours, which tend to occur from 12 pm to 3 pm.

Triple-digit temperatures have reached the West and Southwest, with temperatures as high as 128 degrees Fahrenheit hitting California in recent weeks. When weather conditions align, sizzling temperatures can last for days as a result of hot ocean air being trapped in the atmosphere, also known as a heat dome. Data from the U.S. Energy Information Administration in 2015 shows that only about 64% of U.S. households have access to central air conditioning systems.

Heat domes can cause serious health risks, according to J.D. Zipkin, MD, double board-certified in internal medicine and pediatrics and chief medical officer of GoHealth Urgent Care. "Summer heat waves can present serious risks to human health in the form of heat-related illnesses," Zipkin tells Verywell. "These include heat rashes, fainting, heat exhaustion, and heat stroke."

As a result of excess heat exposure, the body can experience heat stress. Zipkin explains that heat stress is the total environmental risk of experiencing a heat-related illness. When heat-related illnesses are left untreated, Zipkin says that it can damage internal organs and even lead to death. 

Among those most at risk include children and elderly folks. "In general, children are susceptible to exertional heat illnesses due to ongoing play and decreased hydration," Zipkin says. The elderly are also more susceptible because, Zipkin explains, "As we age, the physiologic mechanisms that allow us to cool off—such as diverting more blood to our skin surface—don’t function as well."

Signs and Symptoms of Heat Stress 

Zipkin says that a person may have heat stress if they are experiencing any of the following:

  • Excessive thirst
  • Dry mouth
  • Body temperature over 100.4 degrees Fahrenheit
  • Flushed skin
  • Dizziness
  • Nausea
  • Muscle cramps 

"It is important to note that heat-related illnesses exist on a spectrum, where intervening earlier in the progression reduces the risk of organ injury and improves outcomes," says Zipkin.

Preventing Heat Stress

Gary Gaddis, MD, PhD, emergency medicine physician at Barnes Jewish Hospital in St. Louis, Missouri tells Verywell how people, especially in heat dome areas, can protect themselves from heat-related illnesses. "Because they’re losing more fluid, they need to take in more fluid," Gaddis shares. "So a good rule of thumb is looking at your urine." 

Gaddis says that if their urine is relatively clear, a person is reasonably well-hydrated. For folks with darker urine, he recommends increasing fluid intake. Dehydration occurs when the body loses too much water, which is needed to send blood to the organs. "The more dehydrated a person becomes, the less frequent you have to urinate," Gaddis says. For elderly folks, Gaddis says that taking certain medications can impair the ability to sweat. "So they're going to be more at risk for getting overheated." 

Zipkin says that flavored sports drinks have been found to increase hydration because they replenish salts that were lost while sweating. In addition, Zipkin recommends avoiding exercise and sun exposure during peak temperature hours, which tend to occur from 12 pm to 3 pm, and using fans and wearing light, loose clothing.

Gaddis recommends avoiding exercise in humid environments, too. "Your body’s ability to sweat and evaporate heat is the most efficient way to cool. But if you are in a highly humid environment, any sweat that drips off of you doesn’t evaporate," which can make the body feel so much hotter, Gaddis says. 

According to the Massachusetts Institute of Technology, when relative humidity reaches a high enough level, the body’s natural cooling system will not function. And in extreme conditions, people can begin to experience the aforementioned signs and symptoms of heat stress such as heat cramps and stroke. Instead, Gaddis recommends exercising during cooler times of the day, such as before sunrise or sundown. 

When air conditioning is not readily available, Gaddis recommends visiting a cooling center in your area. A cooling center is a space that is air conditioned or cooled by other means in order to keep communities safe during extreme heat waves, and can be located in a library, school, community center, religious center, private business, or recreation area. Studies have shown that the usage of cooling centers reduces mortality.

Barriers To Cooling Centers

There can be access barriers when it comes to cooling centers, though. For people located in rural areas, research shows that they may be less able or willing to travel to a cooling center, and may lack the transportation needed to get there.

Research also shows that respondents in New York City, Detroit, Phoenix, and Philadelphia were hesitant to go to cooling centers because they were unsure of what a cooling center provides and didn’t want to sit in a room and do nothing.

One way to combat this is to "consider taking a computer, whether it’s going online or playing video games, taking a computer to the shelter or cooling center and riding out the heat that way," Gaddis says. 

The CDC outlined a plan to make cooling centers more accessible, which includes partnerships with public health departments, local government, non-profits, local businesses, departments of transportation, and school systems, as well as education and increased awareness of cooling centers.

Heat Stress Intervention 

"If you or someone you know develops a heat-related illness, move into a cooler environment, somewhere that’s shaded, another air-conditioned building or a car, get hydrated and seek medical attention immediately," says Zipkin. "Most cases of heat-related illness can be reversed with I.V. hydration and rapid core cooling."

What This Means For You

If you or someone you know is experiencing a heat-related illness, experts recommend moving to a cooler environment, getting hydrated, and seeking medical attention immediately. 

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Oceanic and Atmospheric Administration. What is a heat dome?

  2. U.S. Energy Information Administration. Energy use in homes.

  3. Massachusetts Institute of Technology. Why do we sweat more in high humidity?

  4. Centers for Disease Control and Prevention. The use of cooling centers to prevent heat-related illness: summary of evidence and strategies for implementation.

  5. Sampson NR, Gronlund CJ, Buxton MA, et al. Staying cool in a changing climate: Reaching vulnerable populations during heat events. Glob Environ Change. 23(2):475-484. doi:10.1016/j.gloenvcha.2012.12.011

By Kayla Hui, MPH
Kayla Hui, MPH is the health and wellness ecommerce writer at Verywell Health.She earned her master's degree in public health from the Boston University School of Public Health and BA from the University of Wisconsin-Madison.