Three Duke University experts, including Heat Policy Innovation Hub director Ashley Ward, discuss how heat affects health and share how individuals and communities can stay safe. 

Heat waves are becoming longer, stronger, and deadlier than ever. Ashley Ward, director of the Heat Policy Innovation Hub, explained the mechanism to Tech Times: "The baseline is warmer. So, when a heat dome or a high-pressure system sets up, it's now starting from a hotter floor."

Under a heat dome in the eastern half of the United States, millions are suffering through extreme heat, and nights don't bring much relief. Nicholas Institute expert Ashley Ward spoke with NPR's Morning Edition about what makes this heat different and how people can stay safe.

Record-breaking heat waves aren't letting up—even at night. That spells trouble for the body's ability to recover after heat exposure. "We're seeing temperatures well into the evening that are staying shockingly high and, in some cases, never dropping below 80 or 75 degrees," Ashley Ward, director of the Heat Policy Innovation Hub, told NPR. "Our bodies need [recovery time], of course, but plants and animals … also our energy infrastructure. We need to be able to cool off overnight."

Higher average temperatures due to climate change are making heat waves more common and extreme. Vox quotes Nicholas Institute expert Ashley Ward's recent appearance on NPR: “When a heat dome or a high-pressure system sets up, it’s now starting from a hotter floor. That makes the extreme heat more likely.”

There's not an absolute temperature at which extreme heat turns dangerous—humidity and wind flow are also key risk factors, reports NPR. "If it's a very humid day and there's no wind speed, then you are more at risk, even if the air temperature is lower," said Nicholas Institute expert Ashley Ward.

Residents in temperate places like Vermont have been eyeing adding air conditioning to homes that previously didn't need it. But these updates come with a host of other considerations.

“It’s not just whether you can afford an air conditioner," Heat Policy Innovation Hub Director Ashley Ward told VTDigger. "It’s, can the energy providers’ supply meet the increased demand of cooling? Is cooling affordable in those communities to people who haven’t budgeted for needing to air condition their home?”

A heat dome is forecast to bring dangerously high temperatures to millions of Americans over the Fourth of July weekend. Nicholas Institute expert Ashley Ward joined CNN's "News Central" to discuss why heat waves are getting more intense, who is most at risk and what people can do to protect themselves.

Overnight temperatures can be a particularly dangerous part of a heat wave, Nicholas Institute expert Ashley Ward told The Associated Press. For people who can’t afford to cool their whole home, Ward recommended creating a “cool corner” to sleep in. She also offered tips for anyone without access to air conditioning.

The heat wave has already forced summer camps and other outdoor activities in the Midwest to be canceled, according to The Associated Press. "What we're seeing ... is exactly the kind of thing that we can expect going forward," Nicholas Institute expert Ashley Ward told NPR. "The baseline is warmer. So, when a heat dome or a high-pressure system sets up, it's now starting from a hotter floor. And so that makes the extreme heat more likely."

High temperatures early in the heat season can be especially dangerous because people, institutions and daily routines have not fully adjusted to summer conditions, Nicholas Institute expert Ashley Ward told Coastal Review. “Our bodies acclimatize over time, so the temperature can pose a greater health risk in May or June than the same temperature later in the summer,” Ward said. “People may also be less prepared behaviorally.”

When does heat go from being uncomfortable to being dangerous for our bodies? In this Q&A with Ashley Ward, director of Duke University's Heat Policy Innovation Hub, learn how North Carolinians have a newly refined, evidence-based system to lean on as they make decisions about outdoor activities and heat precautions.

It will be important for FIFA to make sure the athletes and conditions for play are safe in stifling heat at this summer's World Cup, but it also will be paramount to give as much attention to the safety of support staff and the fans, Nicholas Institute expert Ashley Ward told North Carolina Health News.

“Those are people who are not, in fact, at their physical peak, most likely," Ward said. “They are not in a position where they have access to perhaps shade and other kinds of structures that mitigate heat exposure.”

The National Weather Service is forecasting the first major heat wave of the year in the Central and Eastern United States this week, potentially endangering the health of tens of millions of people and affecting economic activity. Nicholas Institute expert Ashley Ward joined WPTF Afternoon News to discuss ways to stay safe during the hot weather.

Travelers should be mindful of how their behavior changes on vacation. People often get into trouble when they ignore both environmental conditions and the warning signals their bodies are giving them. “They think they can push through. That is a mistake,” Nicholas Institute expert Ashley Ward told The Associated Press.