People dealing with record summer heat waves across the United States and Europe aren’t getting much of a respite when the sun goes down, reports The Week. In cases where the temperature after sundown doesn’t drop below 75 to 80 degrees, people are “not getting the opportunity for recovery overnight, as we’ve historically seen,” said Nicholas Institute expert Ashley Ward.

California leads the nation in extreme heat policy but still faces key gaps in coordination, funding and protections, according to a new report by Duke University researchers.

Warm nights can pose additional dangers during heat waves. Heat Policy Innovation Hub Director Ashley Ward told WFAE that ensuring a cool sleeping environment can reduce the health risks associated with consecutive days of hot temperatures. “Prioritize cooling your bedroom, because that’s going to be a smaller area to cool, less expensive to cool," she said. "Also, that allows your body to have that important recovery time overnight."

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 AP News. "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."

“At the end of the day, energy security triumphs any other climate considerations,” Nicholas Institute expert Sandeep Pai told AP News. Oil and gas shortages caused by the Iran war have meant much of Southeast Asia is now turning back to coal for energy security, disrupting a trend toward lower-emission electricity generation.

Duke Today featured the work of Duke researchers who are studying ocean solutions critical for long-term ecological health and community stewardship. “Research is important to understand our current ocean state,” said Stephanie Rousso, managing director of Oceans@Duke. “It’s important to build ocean ecosystems and communities that are more resilient to climate change.”