By — Bella Isaacs-Thomas Bella Isaacs-Thomas Leave your feedback Share Copy URL https://www.pbs.org/newshour/health/tips-for-staying-safe-in-extreme-heat Email Facebook Twitter LinkedIn Pinterest Tumblr Share on Facebook Share on Twitter Tips for staying safe in extreme heat Health Jul 26, 2023 4:56 PM EDT Around the world, communities have been contending with record-breaking heat waves and the life-threatening dangers that go along with them. With long-term average temperatures on the rise, and summers getting progressively hotter in many places, the challenge of keeping people safe under extreme heat – and its comparably nefarious cousin, high humidity – will only grow more dire. “It’s not cooling off anytime soon,” said Heidi Brown, associate professor of public health at the University of Arizona. Not too far away, in Phoenix, daily temperatures have reached at least 110°F for more than three weeks straight. Heat stroke, heat exhaustion and heat cramps all fall under the category of heat-related illnesses. In some cases — and always in the case of heat stroke — these conditions require emergency medical attention. According to the National Weather Service, extreme heat is the top weather-related cause of death in the U.S. READ MORE: How extreme heat affects young athletes Anyone can be affected, but people who are socially vulnerable — including those who are elderly, unhoused, working outdoors, incarcerated or low-income — are at particular risk. “We know that there’s this kind of strong relationship between poverty and poor health,” said Diana Hernández, an associate professor of sociomedical sciences and co-director of the Energy Opportunity Lab at Columbia University. “And so you have folks that are already compromised in their health status — you need cooling to be healthy and, in some cases, stay alive.” A sign reading ‘Today’s High: 115’ is posted in South Mountain Park amid a record-breaking heat wave in Phoenix, Arizona, on July 25, 2023. Photo by Mario Tama/Getty Images Here’s a look at the physiological impacts of heat and humidity, what you can do if you must be outside when they strike and some resources you can turn to if air conditioning isn’t readily accessible. How do extreme heat and humidity affect the body? As warm-blooded mammals, our bodies must maintain a constant temperature, said Chris Uejio, an associate professor of geography at Florida State University. That temperature typically hovers somewhere between 97 and 99 degrees Fahrenheit. “When our environment becomes hotter than our internal core body temperature, and/or we’re creating heat from metabolic activities, our body temperature will rise,” Uejio said. If the brain senses too much heat in the body’s core, a couple different systems can kick in to cool it down. The heart can speed up to pump blood out to the extremities in an effort to transfer heat away from the core, and blood vessels can carry more blood near the skin’s surface for the same reason, Uejio explained. That allows some of that excess heat to be released into the environment. READ MORE: Farmworkers are dying in extreme heat. Few standards exist to protect them Good old-fashioned sweating is even more effective. When the body generates sweat, that liquid coats the skin and eventually evaporates, a process that cools us down. Uejio noted that it’s the same reason that we feel cooler after stepping out of a shower. But when humidity is high, the air holds more water, making it more difficult for that sweat to evaporate. And when the air fails to efficiently wick sweat from the skin, it can’t take the heat with it, JohnEric Smith, an associate professor of exercise physiology at Mississippi State University. When we get too hot and dehydrated, our cardiovascular system works harder and our kidneys are more stressed. Who’s most at risk when it comes to extreme heat and humidity? Older adults, young children, pregnant people and those with pre-existing medical conditions are all more vulnerable to heat. In the case of older adults, that’s in part because they’re more likely to have underlying health conditions — including some that can increase heat sensitivity — in addition to poor blood circulation. Some of the medications people may take to manage those conditions, Uejio said, can also disrupt the body’s ability to regulate its temperature, as well as how hydrated they stay, in some cases. READ MORE: Extreme heat can be deadly for people who are homeless Infants and young children have smaller bodies, which means they can accumulate heat more rapidly, Uejio said. Kids’ ability to communicate is also more limited, he added, which can make it harder for them to alert their caregivers if they’re overheating. Smith also noted that sweat glands aren’t fully developed until children hit puberty. Extreme heat exposure is linked with adverse outcomes in pregnancy, including preterm birth and low birth weight. Pregnant people also have an increased metabolic rate, Smith said. Their bodies have to work harder to stay cool, and they’re at an increased risk of dehydration, according to the Centers for Disease Control and Prevention. Labor laws regarding extreme heat are patchy. Although federal standards require employers to keep their employees safe, that mandate isn’t specific to any particular environmental conditions, Uejio said. Only a handful of states have some type of occupational heat safety standards. Those standards generally incorporate three key factors, he added: water, rest and shade. Tips for staying safe when it’s extremely hot or humid It’s crucial not to underestimate the risks of extreme heat and humidity. Heat is notoriously sneaky. The early signs of heat exhaustion can sometimes be mistaken for general feelings of malaise or symptoms of other conditions, Uejio said. Graphic by Megan McGrew/PBS NewsHour The body is remarkably adaptable — healthy individuals can acclimate to moderately hot conditions, but that process requires time and exposure. Smith noted that many of us spend a lot of time in air conditioning when it’s hot outside, which means our bodies aren’t necessarily prepared to handle the heat efficiently. Here’s what experts recommend: Proactively hydrate. Don’t wait until you feel thirsty to drink water. Instead, make sure you’re consistently drinking water throughout the day, especially if you have to go outside. Keeping an eye on urine color is a good idea, too. Aim for a pale yellow color — if it’s any darker, drink up. Stay inside, or find some shade. Avoiding direct sunlight or just staying in if you can are both helpful. Replenish the body’s sodium levels, which can be thrown off by heavy sweating. Drinking sports drinks like Gatorade or making an effort to munch on some salty pretzels — in addition to drinking regular water — can help, according to Smith. Pick cooler times of day for outdoor activities. Check when your local temperatures will peak and schedule accordingly. Brown noted that in Arizona, it’s common for people to exercise in the early morning – even before the sun is up – to avoid the hottest parts of the day. Check on your loved ones and neighbors. Keep an eye on people in your community who are more vulnerable to heat, and those who may have inconsistent access to air conditioning, or none at all. If you’re experiencing symptoms of heat-related illness, seek medical attention. Experts say to play it safe when it comes to extreme heat. Underestimating your body’s reaction can be fatal, Smith said, so seeing a doctor is always a good call, even if it ends up being a false alarm. What about the unhoused or those lacking access to air-conditioning? The National Center for Healthy Housing provides this resource with tips on how to find local cooling centers in your state. By — Bella Isaacs-Thomas Bella Isaacs-Thomas Bella Isaacs-Thomas is a digital reporter on the PBS NewsHour's science desk. @bella_is_
Around the world, communities have been contending with record-breaking heat waves and the life-threatening dangers that go along with them. With long-term average temperatures on the rise, and summers getting progressively hotter in many places, the challenge of keeping people safe under extreme heat – and its comparably nefarious cousin, high humidity – will only grow more dire. “It’s not cooling off anytime soon,” said Heidi Brown, associate professor of public health at the University of Arizona. Not too far away, in Phoenix, daily temperatures have reached at least 110°F for more than three weeks straight. Heat stroke, heat exhaustion and heat cramps all fall under the category of heat-related illnesses. In some cases — and always in the case of heat stroke — these conditions require emergency medical attention. According to the National Weather Service, extreme heat is the top weather-related cause of death in the U.S. READ MORE: How extreme heat affects young athletes Anyone can be affected, but people who are socially vulnerable — including those who are elderly, unhoused, working outdoors, incarcerated or low-income — are at particular risk. “We know that there’s this kind of strong relationship between poverty and poor health,” said Diana Hernández, an associate professor of sociomedical sciences and co-director of the Energy Opportunity Lab at Columbia University. “And so you have folks that are already compromised in their health status — you need cooling to be healthy and, in some cases, stay alive.” A sign reading ‘Today’s High: 115’ is posted in South Mountain Park amid a record-breaking heat wave in Phoenix, Arizona, on July 25, 2023. Photo by Mario Tama/Getty Images Here’s a look at the physiological impacts of heat and humidity, what you can do if you must be outside when they strike and some resources you can turn to if air conditioning isn’t readily accessible. How do extreme heat and humidity affect the body? As warm-blooded mammals, our bodies must maintain a constant temperature, said Chris Uejio, an associate professor of geography at Florida State University. That temperature typically hovers somewhere between 97 and 99 degrees Fahrenheit. “When our environment becomes hotter than our internal core body temperature, and/or we’re creating heat from metabolic activities, our body temperature will rise,” Uejio said. If the brain senses too much heat in the body’s core, a couple different systems can kick in to cool it down. The heart can speed up to pump blood out to the extremities in an effort to transfer heat away from the core, and blood vessels can carry more blood near the skin’s surface for the same reason, Uejio explained. That allows some of that excess heat to be released into the environment. READ MORE: Farmworkers are dying in extreme heat. Few standards exist to protect them Good old-fashioned sweating is even more effective. When the body generates sweat, that liquid coats the skin and eventually evaporates, a process that cools us down. Uejio noted that it’s the same reason that we feel cooler after stepping out of a shower. But when humidity is high, the air holds more water, making it more difficult for that sweat to evaporate. And when the air fails to efficiently wick sweat from the skin, it can’t take the heat with it, JohnEric Smith, an associate professor of exercise physiology at Mississippi State University. When we get too hot and dehydrated, our cardiovascular system works harder and our kidneys are more stressed. Who’s most at risk when it comes to extreme heat and humidity? Older adults, young children, pregnant people and those with pre-existing medical conditions are all more vulnerable to heat. In the case of older adults, that’s in part because they’re more likely to have underlying health conditions — including some that can increase heat sensitivity — in addition to poor blood circulation. Some of the medications people may take to manage those conditions, Uejio said, can also disrupt the body’s ability to regulate its temperature, as well as how hydrated they stay, in some cases. READ MORE: Extreme heat can be deadly for people who are homeless Infants and young children have smaller bodies, which means they can accumulate heat more rapidly, Uejio said. Kids’ ability to communicate is also more limited, he added, which can make it harder for them to alert their caregivers if they’re overheating. Smith also noted that sweat glands aren’t fully developed until children hit puberty. Extreme heat exposure is linked with adverse outcomes in pregnancy, including preterm birth and low birth weight. Pregnant people also have an increased metabolic rate, Smith said. Their bodies have to work harder to stay cool, and they’re at an increased risk of dehydration, according to the Centers for Disease Control and Prevention. Labor laws regarding extreme heat are patchy. Although federal standards require employers to keep their employees safe, that mandate isn’t specific to any particular environmental conditions, Uejio said. Only a handful of states have some type of occupational heat safety standards. Those standards generally incorporate three key factors, he added: water, rest and shade. Tips for staying safe when it’s extremely hot or humid It’s crucial not to underestimate the risks of extreme heat and humidity. Heat is notoriously sneaky. The early signs of heat exhaustion can sometimes be mistaken for general feelings of malaise or symptoms of other conditions, Uejio said. Graphic by Megan McGrew/PBS NewsHour The body is remarkably adaptable — healthy individuals can acclimate to moderately hot conditions, but that process requires time and exposure. Smith noted that many of us spend a lot of time in air conditioning when it’s hot outside, which means our bodies aren’t necessarily prepared to handle the heat efficiently. Here’s what experts recommend: Proactively hydrate. Don’t wait until you feel thirsty to drink water. Instead, make sure you’re consistently drinking water throughout the day, especially if you have to go outside. Keeping an eye on urine color is a good idea, too. Aim for a pale yellow color — if it’s any darker, drink up. Stay inside, or find some shade. Avoiding direct sunlight or just staying in if you can are both helpful. Replenish the body’s sodium levels, which can be thrown off by heavy sweating. Drinking sports drinks like Gatorade or making an effort to munch on some salty pretzels — in addition to drinking regular water — can help, according to Smith. Pick cooler times of day for outdoor activities. Check when your local temperatures will peak and schedule accordingly. Brown noted that in Arizona, it’s common for people to exercise in the early morning – even before the sun is up – to avoid the hottest parts of the day. Check on your loved ones and neighbors. Keep an eye on people in your community who are more vulnerable to heat, and those who may have inconsistent access to air conditioning, or none at all. If you’re experiencing symptoms of heat-related illness, seek medical attention. Experts say to play it safe when it comes to extreme heat. Underestimating your body’s reaction can be fatal, Smith said, so seeing a doctor is always a good call, even if it ends up being a false alarm. What about the unhoused or those lacking access to air-conditioning? The National Center for Healthy Housing provides this resource with tips on how to find local cooling centers in your state.