Skip to main content

Fighting Extreme Heat is a Year-Round Job

Duke experts discuss heat wave with media

Fighting Extreme Heat is a Year-Round Job
Ashley Ward and Luke Parsons

DURHAM, N.C. -- Extreme heat from climate change can be mitigated but needs year-round attention with an eye to equity and local solutions, two Duke scientists said Thursday.

Climate health scholars Ashley Ward and Luke Parsons emphasized that while midday high temperatures get much of the attention, overheated evenings can create significant health problems as well for people without air conditioning.

They discussed these and other climate-related issues in a virtual media briefing with journalists.

Watch the briefing on YouTube.

Here are excerpts:


Ashley Ward, climate health scientist

“When overnight temperatures remain high, what we’re seeing is the body doesn’t have a chance to recover from any heat exposure during the day, which starts to trigger a cascading set of events that results in heat-related illness, heat stroke, usually over a matter of days sometimes.”

“In order to address the increasing risk that we see from heat, we need to think about structural changes, not just ‘are individuals doing their part.’ We need to create environments that mitigate that risk above and beyond what individuals can do. This is where community approaches are effective.”


Luke Parsons, earth and climate studies researcher

“Heat exposure, in particular humid heat exposure, is affecting outdoor workers across the globe. What we’re really talking about here oftentimes are agricultural workers, construction workers, maybe outdoor miners or people working in the fracking industry.  People who can’t escape inside to the air conditioning. They’re really impacted during heat waves or just in general when it’s hot and humid during daylight.”

“If you go out in the middle of the day, the heat of the day in late July, it’s hot and humid. If you want to dig a trench in your backyard with a shovel, you generate internal body heat. Your body needs to cool itself or you’ll have some serious health repercussions.”

“If it’s too hot and humid outside though, your body can’t really, as efficiently, lose this heat to the outdoor environment. You’re generating a lot of internal heat from your labor. You have to slow the pace of your work or you’ll really experience severe health consequences.”

“As the globe warms and heat waves get hotter and more frequent, it gets hotter and more humid outside for these workers who try to work outside, and it gets harder and harder for them to safely conduct their work.”

“Given how much we know agricultural and construction workers on average contribute to the U.S. economy, we can estimate this is something like maybe $20-$100 billion of labor productivity losses per year in the U.S. just because people can’t as efficiently and effectively do the work.”


Ashley Ward

“All evidence points to increasing global temperatures, so yes, what we’re experiencing is likely our new normal. It probably will get worse.

Given this, we need to adapt to this new reality by doing things like:

  • increasing tree canopies in urban spaces;
  • making changes to our building codes that require energy efficient buildings for this new normal, and the new normal that’s projected over the 30- to 50-year timeframe;
  • supporting policies that help people increase the energy efficiency in their homes;
  • increasing our protections for occupational heat exposure. And it’s not just outdoor – it’s also manufacturing, which gets pretty hot inside;
  • training for doctors, midwives and nurses about the increased risk from high heat for their pregnant patients.”


Ashley Ward

“The investments of this administration to address extreme heat, probably more than anything I’ve seen in my career, get at both the community level of risk, but also the occupational level of risk.”

“By increasing both the regulations and the enforcement of workplace protections for occupational heat exposure – in the Southeast and particularly in North Carolina – energy poverty and occupational heat play a critical role in the heat, morbidity and mortality that we see.”

“One of the things I’d like to see is a streamlining of these programs available at the federal level and their application process so that it’s easier for local governments and communities to apply for them.”


Ashley Ward

“We actually see people headed to the emergency department at temperatures lower than when emergency warnings were issued by the National Weather Service.

When heat gets [to] 100 degrees for example, people actually do take precautions. It’s at 96, 97 [degrees] when people are not quite as cautious, and that leads to some challenging health outcomes. There isn’t always an alignment with where the health risk lies and where the National Weather Service warnings are.”


Ashley Ward

“What we’re talking about here is a real shift in thinking, away from regulatory  approaches towards an investment. This is important because investment is what’s needed to build production in the U.S. to clean energy. In doing so, it accelerates the transition already underway, and cleverly so, by decreasing the demand for fossil fuels rather than decreasing the supply, which results in something politically difficult, which is driving up the cost.”

Luke Parsons

“The thing I’m really excited about with this is this idea of also providing lower-income communities with the ability to try to cool themselves more effectively. This is an equity issue. The average middle- or upper-class person with more income in North Carolina has probably more air conditioning access than a lower-income person.”

“Protecting people by allowing them to efficiently and more effectively cool themselves during the day and at night is really important.”

“If we can move away from people burning fossil fuels in their homes or burning fossil fuels to drive their cars around, this has really positive impacts for air pollution and reduced air pollution exposure. So not only in the long term could we maybe slow global warming, but right now if we were to basically move away from fossil fuels, we have massive, massive, massive health benefits locally from reduced air pollution exposure.”


Luke Parsons

“We tend to really focus on how hot it gets, just the temperature. It’s really important to note that how humid it is matters, too. If you sweat and you can’t cool yourself when you’re sweating, you’re more likely to experience negative effects of heat. It’s heat and the humidity oftentimes.”

We focus on how hot it is in the middle of the afternoon but more and more research is coming out that it really matters how hot it is overnight. With the cumulative exposure of people to heat overnight, if they can’t let their bodies cool down, their bodies can’t reset and recover from the heat, there are short- and long-term health consequences from that.”

Ashley Ward

“Heat kills more people than any other weather-related event in the U.S. … When the media reports on this, you also see people lying on the beach in the photo, or you see kids running through sprinklers. This really doesn’t convey the risk we’re talking about.  Imagine if we talked about a hurricane in that way. I think it’s really important that whatever we’re communicating about heat, we’re communicating in a way that people understand what the risk is.”

“Understanding who is vulnerable to heat and how they’re vulnerable varies considerably in the U.S., and I think that’s one big misconception people have."

In the Southeast, we struggle with chronic heat exposure … while in the Pacific Northwest or the Midwest it might be acute heat wave events. In North Carolina, heat-related illness events are much higher in rural areas than they are in urban areas.”

“In other regions of the nation, we’re talking about urban centers that bear the brunt of heat, morbidity and mortality.”

“It’s important that while there are things we can do to support national strategies for mitigation and resilience for heat … we need to recognize that the experience of heat and the solutions for extreme heat must come from more localized perspective.”


Luke Parsons

“In addition to providing shade, trees also cool the surrounding environment … if you go in and clear-cut a large area, there’s not only a lack of shade, but the trees aren’t there cooling the local atmosphere.”


Luke Parsons

“With every degree of climate change, if we don’t slow it, the impacts spread geographically and get higher magnitude and intensify locally. The more that we can limit warming in the long term, the more we can protect ourselves as we’re getting older, and future generations because it’s just going to get worse.”

“Throwing up our hands and saying ‘let’s burn all the coal because it doesn’t matter,’ you’re putting future generations at even greater risk.”


Ashley Ward

“In February, nobody wants to talk about heat. I look out my window and it looks pretty much the same when it’s 85 degrees as it does when it’s 100 degrees. Mitigating and building resilience around heat requires more attention than just May to September.”

“We don’t just plan for hurricane season during hurricane season. We plan and mitigate for hurricane season all year long. We have to do the same thing about heat. Changing our perspective on who is vulnerable, how and why, is critically important.”

Luke Parsons

“It’s a health equity issue.”

“Many people who are most vulnerable to heat exposure don’t have access to air conditioning. Sometimes people don’t have access to the cooling methods they need in a warming world.”

The participants

Luke Parsons
Luke Parsons is a research scientist and lecturer in the division of earth and climate sciences in the Nicholas School of the Environment at Duke, where he studies climate and air pollution impacts on human health and well-being. 

Ashley Ward
Ashley Ward is the senior policy associate with the Nicholas Institute for Energy, Environment and Sustainability. Her career has focused on engaging communities to identify and address issues, and helping communities develop long-term, sustainable strategies. Her previous work with NOAA’s Carolinas RISA team connected rural and urban communities and policy-decision makers with relevant climate and health data, particularly related to vulnerabilities and impacts.