This week, the CDC released new guidelines for mask use in the U.S., just months after many cities and towns relaxed mask mandates. The guidance says that “to reduce their risk of becoming infected with the Delta variant and potentially spreading it to others: CDC recommends that fully vaccinated people wear a mask in public indoor settings if they are in an area of substantial or high transmission.”

Right now, many parts of the country fall under that category. In response to the guidance, several municipalities re-instituted mask mandates for their communities.

This week, New York chose to require either COVID-19 vaccination or weekly testing for public employees. Other municipalities have also announced vaccine requirements—and some private companies, including Facebook, have also indicated that vaccination will be required for employment.

Sophie Bushwick, technology editor at Scientific American, joins guest host Roxanne Khamsi to talk about the new rules and other stories from the week in science, including studies of clouds and climate change, Olympic psychology, and caffeinated bees.

Throughout the pandemic, scientists have been learning more about SARS-CoV-2, the virus that causes COVID. But there are still big questions, like how long the virus can survive in your body.

This week, infectious disease specialist Diane Griffin talks about how viruses—from SARS-CoV-2 to HIV to measles—persist in the body, and how this can provide new insights into how long people might stay contagious.

As climate change amplifies the risks of natural hazards like wildfires, hurricanes, drought, and more, there’s a group of scientists hoping to change the way the United States responds to the disasters that often result.

They are disaster researchers: the people who study the engineering, sociology, and even psychology of what makes the difference between an easily handled hurricane, and a catastrophe like Hurricane Maria, which wiped out infrastructure, destroyed 800,000 homes, and killed an estimated 5,000 people in Puerto Rico in 2017.

Emergency management researcher Samantha Montano is the author of the forthcoming book Disasterology: Dispatches from the Frontlines of the Climate Crisis. She talks to producer Christie Taylor about the nuts and bolts of preparing for a disaster, how climate change is changing the equation, and how justice in disaster response will be more important than ever.