As temperatures break records, many are unaware of symptoms of heat-related illnesses

With NASA data showing that July 22, 2024, was the hottest day on record and indications that July may have been the hottest month, an Annenberg Public Policy Center survey conducted in mid-July found that most people know three of the symptoms of a heat-related illness but do not know the location of their nearest cooling center. At the same time, increasing numbers of people think that heat waves are becoming more frequent and intense and affecting their daily activities.

Knowledge of cooling centers in the case of extreme heat

Although the locations of cooling centers, or indoor air-conditioned facilities such as libraries, community and senior centers, schools are publicized by city governments on hot days, many of those surveyed report being unaware of where to find one. Two-thirds of respondents (67%) say they do not know the location of a cooling center to which they could go to in case of extreme heat, a number statistically unchanged from last November. "Communities must do a better job of making the public, especially the most vulnerable, aware of these centers," said Ken Winneg, managing director of survey research at APPC.

More today see link between extreme heat and climate change.

When compared with an APPC survey in November 2023, significantly more people now say that climate change is increasing the risk of heat-related illnesses, respiratory diseases, and insect-borne diseases. Two-thirds (67%) hold this view vs. just under 6 in 10 (58%) in November 2023.

More people indicate that heat waves in the United States are becoming more frequent and intense than in the past. About two-thirds (65%) believe heat waves are becoming more frequent and intense. Fifty-eight percent (58%) felt this way in November 2023, when we last asked the question. About a quarter (24%) believe heat waves are about as frequent and intense as they have always been, statistically unchanged from our earlier survey.

At the same time, the proportion of people who say extreme heat has often or frequently affected their typical daily activities in the past year has increased significantly. Forty-three percent (43%) say extreme outdoor heat has often (22%) or frequently (21%) affected their daily activities, an 8-point increase compared with November 2023 (35% in total said either "often" or "frequently").

Signs of heat-related illnesses

Notably, most people also know three of the telltale signs of heat-related illnesses:

• Dizziness (89% compared to 86% in August 2022)
• Nausea (83% compared to 79% in August 2022)
• Hot, red, dry, or damp skin (72%, statistically unchanged from August 2022)
• Cold, pale, and clammy skin (42%, statistically unchanged from August 2022).

Public understands some extreme heat risks better than others

Thinking about the next 10 years, just under 6 in 10 (58%) think that people in their community will be more likely to experience heat stroke caused by extreme heat waves. This is significantly higher than in November 2023 when just over half (52%) said they thought people in their community would be more likely to experience heat stroke caused by extreme heat waves in the next 10 years.

However, only 3 in 10 (30%) know that a pregnant person in the U.S. who is exposed to extreme heat is more likely to deliver their baby early than a pregnant person who is not exposed to extreme heat. About a quarter (23%) incorrectly say that a pregnant person in the U.S. is either less or just as likely to deliver a baby early. Forty-seven percent (47%) are unsure which is correct.

Broad awareness that heat-related deaths are most common among seniors

Two-thirds (67%) know that heat-related deaths are most common among older adults, aged 65 or older, slightly but significantly higher than in August 2022 (62%).

Preventing heat-related illnesses

Nearly all (92%) know that drinking water is better to prevent heat-related illnesses than drinking sugary drinks.

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New research explores future limits of survival and livability in extreme heat conditions

Commonly associated with longer days and slower paces, this summer's record-smashing heat in Arizona demonstrated a concerning future for the planet's warmest season. From power outages endangering entire neighborhoods and heat-related deaths rising among some of the state's most vulnerable populations, the city of Phoenix found itself in national headlines. As national attention grew, one question became clear: How does anyone live there?

The consequences of extreme heat do not affect Arizona residents alone.

Extreme heat made worldwide news this year, including in November when a 23-year-old woman died of cardiorespiratory arrest at a Taylor Swift concert in Brazil where heat indexes that day exceeded 120 degrees.

Jennifer Vanos, associate professor in the School of Sustainability at Arizona State University, studies extreme heat and its health impacts.

She is the lead author of a new paper published Nov. 29 in Nature Communications. Titled "A physiological approach for assessing human survivability and liveability to heat in a changing climate," the paper explores temperatures at which humans can survive.

The research demonstrates that the current estimated upper temperature and humidity limits used for human survivability may not paint an accurate picture of the impacts of a warming planet on human health.

"For the past decade or so we have been using what we call a 'wet bulb temperature' of 35 degrees Celsius, or 95 degrees Fahrenheit, as the limit for human survivability," said Vanos, also a Senior Global Futures Scientist in the Julie Ann Wrigley Global Futures Laboratory.

The wet-bulb temperature limit for human survival indicates the maximum combinations of temperature and humidity that humans can tolerate without suffering inevitable heat stroke over a fixed duration of exposure.

"The idea is that you could survive for up to six hours at that level of heat exposure," Vanos said.

"That number really oversimplifies what happens physiologically in the body when your body is exposed to that temperature, and it doesn't account for important variables like age or other vulnerability factors."

Vanos said the commonly-used wet-bulb temperature for human survivability assumes the person is indoors or shaded, unclothed, completely sedentary, fully heat acclimatized and of an "average size." These assumptions do not align, in most cases, with how humanity navigates the summer season.

The paper models scenarios that adjust for factors such as humidity, age, activity level and sun exposure, and provides a range of safe temperatures based on a series of characteristics.

"We didn't only want to better understand the conditions that people could survive in," Vanos said.

"We wanted to understand the conditions that allowed people to live their lives. If the only safe way to live in an area is to be completely sedentary, people won't want to live there. Being able to spend time outdoors and live your life without seeing a sustained rise in core temperature is a really important metric to understand today and as we move into the future."

Vanos said Gisel Guzman Echavarria, an ASU student, was instrumental in creating the figures used throughout the paper to demonstrate the research findings.

The research, funded by the National Science Foundation, was conducted by a combination of climate scientists and physiologists, a collaboration that Vanos said was crucial in understanding the intertwined nature of heat and human health.

Ollie Jay, professor and director of the Heat and Health Research Incubator at the University of Sydney, said the combined perspectives allow for a cohesive understanding of exactly how climate outcomes can impact people on the physiological and biophysical level.

"The existing wet-bulb temperature estimate of 35 degrees Celsius is used very commonly, with one example being the Intergovernmental Panel on Climate Change report," said Jay, senior author of the paper.

"These kinds of reports can shape policy efforts, but they are using a model for heat that is a very conservative estimate of what the impacts are going to be on humans. If we start using a more realistic, human-based model, the impacts are going to be more severe. They're going to be more widespread and they're going to happen sooner than we are projecting."

Vanos and Jay agree that the survivability ranges provided in the paper can give an important glimpse into the future: one that includes an increased need for cooling infrastructure, a personalized approach to heat protection and possible heat-driven migration.

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Climate-driven extreme heat may make parts of Earth too hot for humans

If global temperatures increase by 1 degree Celsius (C) or more than current levels, each year billions of people will be exposed to heat and humidity so extreme they will be unable to naturally cool themselves, according to interdisciplinary research from the Penn State College of Health and Human Development, Purdue University College of Sciences and Purdue Institute for a Sustainable Future.

Results from a new article published today (Oct. 9) in Proceedings of the National Academy of Sciences indicated that warming of the planet beyond 1.5 C above preindustrial levels will be increasingly devastating for human health across the planet.

Humans can only withstand certain combinations of heat and humidity before their bodies begin to experience heat-related health problems, such as heat stroke or heart attack. As climate change pushes temperatures higher around the world, billions of people could be pushed beyond these limits.

Since the start of the industrial revolution, when humans began to burn fossil fuels in machines and factories, temperatures around the world have increased by about 1 C, or 1.8 degrees Fahrenheit (F). In 2015, 196 nations signed the Paris Agreement which aims to limit worldwide temperature increases to 1.5 C above pre-industrial levels.

The researcher team modeled global temperature increases ranging between 1.5 C and 4 C -- considered the worst-case scenario where warming would begin to accelerate -- to identify areas of the planet where warming would lead to heat and humidity levels that exceed human limits.

"To understand how complex, real-world problems like climate change will affect human health, you need expertise both about the planet and the human body," said co-author W. Larry Kenney, professor of physiology and kinesiology, the Marie Underhill Noll Chair in Human Performance at Penn State and co-author of the new study. "I am not a climate scientist, and my collaborators are not physiologists. Collaboration is the only way to understand the complex ways that the environment will affect people's lives and begin to develop solutions to the problems that we all must face together."

A threat to billions

The ambient wet-bulb temperature limit for young, healthy people is about 31 C, which is equal to 87.8 F at 100% humidity, according to work published last year by Penn State researchers. However, in addition to temperature and humidity, the specific threshold for any individual at a specific moment also depends on their exertion level and other environmental factors, including wind speed and solar radiation. In human history, temperatures and humidity that exceed human limits have been recorded only a limited number of times -- and only for a few hours at a time -- in the Middle East and Southeast Asia, according to the researchers.

Results of the study indicate that if global temperatures increase by 2 C above pre-industrial levels, the 2.2 billion residents of Pakistan and India's Indus River Valley, the one billion people living in eastern China and the 800 million residents of sub-Saharan Africa will annually experience many hours of heat that surpass human tolerance.

These regions would primarily experience high-humidity heatwaves. Heatwaves with higher humidity can be more dangerous because the air cannot absorb excess moisture, which limits sweat evaporates from human bodies and moisture from some infrastructure, like evaporative coolers. Troublingly, researchers said, these regions are also in lower-to-middle income nations, so many of the affected people may not have access to air conditioning or any effective way to mitigate the negative health effects of the heat.

If warming of the planet continues to 3 C above pre-industrial levels, the researchers concluded, heat and humidity levels that surpass human tolerance would begin to affect the Eastern Seaboard and the middle of the United States -- from Florida to New York and from Houston to Chicago. South America and Australia would also experience extreme heat at that level of warming.

At current levels of heating, the researchers said, the United States will experience more heatwaves, but these heatwaves are not predicted to surpass human limits as often as in other regions of the world. Still, the researchers cautioned that these types of models often do not account for the worst, most unusual weather events.

"Models like these are good at predicting trends, but they do not predict specific events like the 2021 heatwave in Oregon that killed more than 700 people or London reaching 40 C last summer," said lead author Daniel Vecellio, a bioclimatologist who completed a postdoctoral fellowship at Penn State with Kenney. "And remember, heat levels then were all below the limits of human tolerance that we identified. So, even though the United States will escape some of the worst direct effects of this warming, we will see deadly and unbearable heat more often. And -- if temperatures continue to rise -- we will live in a world where crops are failing and millions or billions of people are trying to migrate because their native regions are uninhabitable."

Understanding human limits and future warming

Over the last several years, Kenney and his collaborators have conducted 462 separate experiments to document the combined levels of heat, humidity and physical exertion that humans can tolerate before their bodies can no longer maintain a stable core temperature.

"As people get warmer, they sweat, and more blood is pumped to their skin so that they can maintain their core temperatures by losing heat to the environment," Kenney said. "At certain levels of heat and humidity, these adjustments are no longer sufficient, and body core temperature begins to rise. This is not an immediate threat, but it does require some form of relief. If people do not find a way to cool down within hours, it can lead to heat exhaustion, heat stroke and strain on the cardiovascular system that can lead to heart attacks in vulnerable people."

In 2022, Kenney, Vecellio and their collaborators demonstrated that the limits of heat and humidity people can withstand are lower than were previously theorized.

"The data collected by Kenney's team at Penn State provided much needed empirical evidence about the human body's ability to tolerate heat. Those studies were the foundation of these new predictions about where climate change will create conditions that humans cannot tolerate for long," said co-author Matthew Huber, professor of earth, atmospheric and planetary sciences at Purdue University.

When this work was published, Huber, who had already begun work on mapping the impacts of climate change, contacted Vecellio about a potential collaboration. Huber had previously published widely cited work proposing a theoretical limit of humans' heat and humidity limits.

The researchers, along with Huber's graduate student, Qinqin Kong, decided to explore how people would be affected in different regions of the world if the planet warmed by between 1.5 C and 4 C. The researchers said that 3 C is the best estimate of how much the planet will warm by 2100 if no action is taken.

"Around the world, official strategies for adapting to the weather focus on temperature only," Kong said. "But this research shows that humid heat is going to be a much bigger threat than dry heat. Governments and policymakers need to re-evaluate the effectiveness of heat-mitigation strategies to invest in programs that will address the greatest dangers people will face."

Staying safe in the heat

Regardless of how much the planet warms, the researchers said that people should always be concerned about extreme heat and humidity -- even when they remain below the identified human limits. In preliminary studies of older populations, Kenney found that older adults experience heat stress and the associated health consequences at lower heat and humidity levels than young people.

"Heat is already the weather phenomenon that kills the most people in the United States," Vecellio, now a postdoctoral researcher at George Mason University's Virginia Climate Center, said. "People should care for themselves and their neighbors -- especially the elderly and sick -- when heatwaves hit."

The data used in this study examined the body's core temperatures, but the researchers said that during heatwaves, people experience health problems from other causes as well. For example, Kenney said that most of the 739 people who died during Chicago's 1995 heatwave were over 65 and experienced a combination of high body temperature and cardiovascular problems, leading to heart attacks and other cardiovascular causes of death.

Looking to the future

To stop temperatures from increasing, the researchers cite decades of research indicating that humans must reduce the emission of greenhouse gases, especially the carbon dioxide emitted by burning fossil fuels. If changes are not made, middle-income and low-income countries will suffer the most, Vecellio said.

As one example, the researchers pointed to Al Hudaydah, Yemen, a port city of more than 700,000 people on the Red Sea. Results of the study indicated that if the planet warms by 4 C, this city can expect more than 300 days when temperatures exceed the limits of human tolerance every year, making it almost uninhabitable.

"The worst heat stress will occur in regions that are not wealthy and that are expected to experience rapid population growth in the coming decades," Huber said. "This is true despite the fact that these nations generate far fewer greenhouse gas emissions than wealthy nations. As a result, billions of poor people will suffer, and many could die. But wealthy nations will suffer from this heat as well, and in this interconnected world, everyone can expect to be negatively affected in some way."

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Measuring the extent of global droughts in unprecedented detail

While some parts of the world suffer extreme heat and persistent drought, others are being flooded. Overall, continental water volumes vary so much over time that global sea levels fluctuate significantly too. By combining the hydrological model WaterGAP with GRACE satellite data, a team of geodesists at the University of Bonn have come up with a new set of data that shows how the total distribution of water over the Earth's land surfaces has changed over the past 20 years more accurately than ever before. Their findings are now being published in the Journal of Geodesy.

"The new method allows us to test out model calculations on the future effects of climate change, particularly how rising temperatures and changes in precipitation patterns will impact the water balance in different parts of the world," says Prof. Dr.-Ing. Jürgen Kusche from the Institute of Geodesy and Geoinformation at the University of Bonn. The process involves comparing climate models, which invariably cover a certain period of time in the past, with the results of actual measurements, and Kusche and his team are planning several such studies over the coming months.

The improved resolution that the team has achieved shows that droughts are significantly more common across the world than the GRACE satellite data would suggest in isolation. "What we're seeing is that even extensive droughts like the massive one that struck the whole of the Amazon in 2010 are spread across much wider areas than the satellite data indicates on its own," Kusche says. "This means that the satellites aren't picking up many of the more localized droughts."

Working together with counterparts from Goethe University Frankfurt and the Polish capital Warsaw, a team of researchers from the University of Bonn has now combined satellite measurements with high-resolution meteorological data for the first time. "What's special about this method is that it's enabled us to improve the resolution of the water distribution maps that are generated from around 300 kilometers to 50 kilometers," explains Kusche, who is a member of the Modelling and Sustainable Futures Transdisciplinary Research Areas and the Regional Climate Change Collaborative Research Center at the University of Bonn. To do so, the researchers used the "WaterGAP" hydrological model developed at Goethe University Frankfurt plus a mathematical technique borrowed from weather forecasting.

Masses of water causing changes in the gravitational field

Between 2002 and 2017, the GRACE (Gravity Recovery and Climate Experiment) twin satellites measured changes in the Earth's gravitational force. Its successor project, "GRACE-FO," launched in 2018, and it was this data that the researchers from the University of Bonn used. Since the Earth's gravitational force is dependent on changes in mass, this allows conclusions to be drawn about the water cycle close to its surface. Gravity is affected by changes in groundwater and surface reservoirs and by melting glaciers.

"One unique advantage of the GRACE measurements is that they cover all kinds of reservoir, i.e. including changes in groundwater reserves that are hidden deep below the Earth's surface and in tens of thousands of artificial lakes and wetlands," says Kusche's colleague Helena Gerdener. The disadvantage, she says, is that the spatial resolution of the data on the gravitational field is relatively inexact at about 300 to 350 kilometers as a result of the measurement principle applied. This means that reliable statements can only be made for areas around 100,000 square kilometers in size. To give some idea of scale, this minimum area is still larger than Bavaria, Germany's largest federal state at "only" 70,000 or so square kilometers.

By contrast, global hydrological models permit a resolution of 50 kilometers or even less. These use meteorological measurements of precipitation, temperature and radiation as well as maps of land use and soil composition and data on how water is being used by industry, agriculture and other consumers. Hydrological models simulate evaporation as well as changes to water levels in the soil and groundwater-bearing strata, lakes, rivers and reservoirs. "However, the drawbacks of these models are that they can only reflect reality to a limited extent and meteorological measurements often contain systematic errors," Kusche says, for example if no data on the extraction of groundwater is made available.

For the first time, the researchers have now combined measurements from the GRACE and GRACE-FO satellites with the WaterGAP hydrological model, which itself integrates high-resolution meteorological data. This has enabled the resolution of the water distribution maps thus generated to be improved to 50 kilometers. To do so, the researchers used a mathematical technique known as data assimilation, which is more usually to be found in weather forecasting. However, the scientists did not simply take the results of the hydrological model and the satellite data and calculate the average values. As Kusche explains: "The calculations from the hydrological model are adjusted so that you get close to the satellite data while modifying the physics that the hydrological model draws on as little as possible."

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An early warning system for joint heat and ozone extremes in China

High temperatures exacerbate ground-level ozone production, resulting in a deadly combination of extreme heat and poor air quality that is especially dangerous for children, seniors, and people suffering from preexisting respiratory illnesses.

Like most of the globe, China is dealing with increasing temperatures and longer and more frequent heat waves. But, because of its rapid, energy-intensive development, it's also seeing increased production of the main precursors of ozone, volatile organic compounds (VOCs) and oxides of nitrogen (NOx). In a country as populous as China, this combination poses a serious threat to human health, especially in large urban areas such as Beijing.

Now, a team of collaborating researchers from the Harvard-China Project at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and Hong Kong Baptist University has identified large-scale climate patterns that could be used to predict the co-occurrence of extreme heat and ozone days in China months before they occur. Like predictions for hurricane and wildfire seasons, the forecasts could help the government prepare resources and implement policies to mitigate the severity of the season.

The research was published recently in the Proceedings of the National Academy of Sciences.

"We've already seen record-breaking heat waves around the globe this summer, including in China, where local emissions have led to substantial ozone pollution," said Fan Wang, a visiting fellow at SEAS and the Harvard-China Project, Ph.D. candidate at Hong Kong Baptist University, and co-lead author of the study. "Our research could have important implications in the future that would allow agencies such as the Ministry of Ecology and Environment in China to prepare for high summer heat and ozone in springtime."

The research team, led by Michael McElroy, the Gilbert Butler Professor of Environmental Studies at SEAS and the faculty chair of the Harvard-China Project, and Meng Gao, professor at Hong Kong Baptist University and former postdoctoral researcher at SEAS, looked to past meteorological data and daily ozone levels to spot patterns that could be used to predict the season.

Because of the lack of long-term daily observations of ground-level ozone concentrations, the researchers used a sophisticated machine learning model to reconstruct levels back to 2005. Using this dataset, the team identified patterns in sea surface warming in the western Pacific Ocean, the western Indian Ocean and the Ross Sea, off the coast of Antarctica, that preceded summers with high heat and ozone in northeast China, including Beijing.

Warm sea surface temperatures in these regions lead to a decrease in precipitation, cloud cover and circulation across this region of China, known as the North China Plain, which is home to roughly 300 million people.

"These sea surface temperature anomalies influence precipitation, radiation and more, which modulate the co-occurrence of heat waves and ozone pollution," said Gao, co-first author of the paper and Associate of the Harvard-China Project.

The team's model correlated these anomalies with increases in heat waves and ozone about 80 percent of the time.

Governmental agencies could use these predictions to not only issue warnings for human health and agriculture but to reduce the components of ozone and its precursors in the atmosphere before the extreme heat waves hit.

"The ability to forecast prospects for unusually hot summers and unusually high levels of summertime ozone in China simply on the basis of patterns of temperature observed months earlier in remote regions of the ocean is truly exciting," said McElroy.

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For outdoor workers, extreme heat poses extreme danger

Working outdoors during periods of extreme heat can cause discomfort, heat stress, or heat illnesses -- all growing concerns for people who live and work in Southwestern cities like Las Vegas, where summer temperatures creep higher each year. But, did you know that female outdoor workers are experiencing disproportionate impacts? Or, that more experienced outdoor workers are at higher risk than those with fewer years on the job?

In a new study in the International Journal of Environmental Science and Technology, scientists from DRI, Nevada State College, and the Guinn Center for Policy Priorities explore the growing threat that extreme heat poses to workforce health in three of the hottest cities in North America -- Las Vegas, Los Angeles, and Phoenix. Their study results hold important findings for outdoor workers, their employers, and policymakers across the Southwestern U.S.

To assess the relationship between extreme heat and nonfatal workplace heat-related illness, the study compared data on occupational injuries and illnesses for the years 2011-2018 with heat index data from Las Vegas, Los Angeles, and Phoenix. Heat index data combines temperature and humidity as a measure of how people feel the heat.

"We expected to see a correlation between high temperatures and people getting sick -- and we found that there was a very clear trend in most cases," said lead author Erick Bandala, Ph.D., assistant research professor of environmental science at DRI. "Surprisingly, this type of analysis hadn't been done in the past, and there are some really interesting social implications to what we learned."

First, the research team analyzed changes in heat index data for the three cities. They found a significant increase in heat index at two of the three locations (Phoenix and Las Vegas) during the study period, with average heat index values for June-Aug climbing from "extreme caution" in 2012 into the "danger" range by 2018. Over the same period, data from the Bureau of Labor and Statistics showed that the number of nonfatal heat-related workplace injuries and illnesses in each of the three states increased steadily, climbing from below the national average in 2011 to above the national average in 2018.

"Our data indicate that the increases in heat are happening alongside increases in the number of nonfatal occupational injuries across these three states," Bandala said. "Every year we are seeing increased heat waves and higher temperatures, and all of the people who work outside in the streets or in gardens or agriculture are exposed to this."

Next, the study team looked deeper into the data to learn about the number of male and female workers being affected by heat-related workplace injuries. At the beginning of the study in 2011, 26 to 50 percent of the people affected across the three states were female. By 2018, 42 to 86 percent of the people affected were female.

Study authors believe that the reason for this increase may be due to more women entering the outdoor workforce, or it could be related to the vulnerability of women to certain heat-related effects, like hyponatremia -- a condition that develops when too much plain water is consumed under high heat conditions and sodium levels in blood get too low.

"As the number of female workers exposed to extreme temperatures increases, there is an increasing need to consider the effect of gender and use different approaches to recommend prevention measures as hormonal factors and cycles that can be exacerbated during exposure to extreme heat," said study coauthor Kebret Kebede, M.D., associate professor of biology at Nevada State College.

The authors examined other variables, such as the length of an employee's service with an employer. They found that the number of heat-related injury/illnesses tended to increase as the length of service with the employer increased, and that those with more than five years of service were at greater risk than those with less than one year of service. This may be due to employees with more years of service having a reduced perception of risk, or could be a cumulative effect of years of chronic heat exposure on the well-being of outdoor workers.

In severe cases, heat-related illness or injury can cause extensive damage to all tissues and organs, disrupting the central nervous system, blood-clotting mechanisms, and liver and kidney functions. In these cases, lengthy recoveries are required. The authors found concerning evidence that heat-related injuries are keeping many outdoor workers away from work for more than 30 days.

"These lengthy recovery times are a significant problem for workers and their families, many of whom are living day-to-day," Bandala said. "When we have these extreme heat conditions coming every year and a lot of people working outside, we need to know what are the consequences of these problems, and we need the people to know about the risk so that they take proper precautions."

The study also explored connections between heat-related injuries/illnesses and the number of hours worked, the time of day that the event occurred, and the ethnicities and age groups that were most impacted.

Study authors hope that their results will be useful to policymakers to protect outdoor workers. They also hope that the information will be useful to outdoor workers who need to stay safe during times of extreme heat, and employers who rely on a healthy workforce to keep their businesses operating.

"This study underscores the importance of and the need for the work the Nevada Occupational Safety and Health Administration (OSHA) is doing to adopt a regulation to address heat illness," stated Nancy Brune, Ph.D., study co-author and senior fellow at the Guinn Center.

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