A worker with Haiti's Ministry of Public Health and Population checks the temperature of a Haitian man coming from the Dominican Republic on March 5. Andres Martinez Casares/Reuters hide caption

Sure, you can sing "Happy Birthday" twice to time your hand-washing — but one hand-washer recommends a 20-second excerpt from Beyoncé's "Love on Top." Kevin Mazur/Getty Images for Coachella hide caption

Ballet dancers in Shanghai rehearse while wearing masks on March 2. A virus first identified in December has altered daily life and public spaces around the globe. TPG/Getty Images hide caption

On Feb. 4, beds were installed in the Wuhan Keting Exhibition Center. With 2,000 beds planned, the center will accommodate patients with mild cases of COVID-19. Stringer for NPR hide caption

This aerial photo was taken on February 2, the day before Huoshenshan hospital was scheduled to open as a treatment center for coronavirus patients. AFP via Getty Images hide caption

A man rides past the Huanan Seafood Wholesale Market in Wuhan, China, which was closed after being linked to cases of a newly discovered coronavirus. Getty Images hide caption

From left: Sekou Sheriff, of Barkedu village in Liberia, whose parents died at an Ebola treatment center; a polio vaccination booth in Pakistan; a schoolgirl in Ethiopia examines underwear with a pocket for a menstrual pad; an image from a video on the ethics of selfies; Consolata Agunga goes door-to-door as a community health worker in her village in Kenya. From left: John Poole/NPR; Jason Beaubien/NPR; Courtesy of Be Girl Inc.; SAIH Norway/Screenshot by NPR; Marc Silver/NPR hide caption

Patients line up for remote health consultation sessions on a remote island near Rangpur, Bangladesh. Allison Joyce for NPR hide caption

Gefilte fish ... made from canned tuna. Marc Silver/NPR hide caption

Computer illustration of malignant B-cell lymphocytes seen in Burkitt's lymphoma, the most common childhood cancer in sub-Saharan Africa. Kateryna Kon/Science Photo Library/Getty Images hide caption

Guns collected in an effort to buy back firearms in Anaheim, Calif., in 2016. The police department obtained 676 guns and gave out $100 gift cards in exchange. The U.S. rate of deaths from gun violence, at 4.43 deaths per 100,000 people, it is four times higher than the rates in war-torn Syria and Yemen. Jeff Gritchen/MediaNews Group/Orange County Register via Getty Images hide caption

A fisherman's boat makes its way across Lake Chilwa in Malawi. A large portion of Lake Chilwa dries out every year, and the fishing industry disappears along with it. Most fishermen then head to Lake Malawi, where there is fishing year-round. Julia Gunther hide caption

Kennedy Odede and Jessica Posner Odede during their countdown to parenthood. June July hide caption

This man is wading from house to house in the Wimbi neighborhood of the city of Pemba, one of the hardest hit by flooding. He and others helped residents bring their possessions to higher ground. Tommy Trenchard for NPR hide caption

Trying to make the world a better place: (left to right) Skoll Award winners Gregory Rockson of mPharma, Nicola Galombik and Maryana Iskander of Harambee Youth Employment Accelerator, Nancy Lublin of Crisis Text Line, Bright Simons of mPedigree and Julie Cordua of Thorn. Greg Smolonski/Skoll hide caption