Could ice shanties like this one, built on Wisconsin's Lake Waubesa in 2005, be considered something of an economic indicator? Joseph W. Jackson III/Wisconsin State Journal via AP hide caption

itoggle caption Joseph W. Jackson III/Wisconsin State Journal via AP

Alexander Kendrick stands in the Lake of the Clouds after testing his invention. He and the team of cavers executed the deepest known digital communication ever to take place in the United States. Brad Horn for NPR hide caption

itoggle caption Brad Horn for NPR

Studies show that only about 40 percent of health care workers in the U.S. wash their hands as often as they should. Rob Carr/AP hide caption

itoggle caption Rob Carr/AP

U.S. Navy and Air Force personnel prepared to airlift a girl with head injuries to an offshore medical facility last week in Port-au-Prince, Haiti. The U.S. military says it halted flights carrying Haitian earthquake victims to the United States on Wednesday. Gregory Bull/AP hide caption

itoggle caption Gregory Bull/AP