Three-quarters of Americans have been urged or ordered to stay at home, to the extent possible, to stop the spread of the COVID-19 coronavirus, and those measures appear to be working, The New York Times reports, citing data from internet-connected thermometer company Kinsa. The thermometers and their app upload temperature readings to a centralized database, allowing Kinsa to track fevers across the country. It started mapping fevers to catch flu outbreaks in 2018, and it modified its software to look for "atypical" COVID-19 fevers earlier in March.

Kinsa's million-plus thermometers have been recording up to 162,000 readings from around the U.S. each day since the coronavirus started spreading, the Times reports. Only strict social-distancing measures — closing bars and restaurants, asking people to shelter in place — led to a significant drop in fever readings, while declaring a state of emergency or limiting the size of public gatherings had little effect. Data from New York and Washington State's health departments have buttressed Kinsa's findings, showing drops in hospitalizations a few days after Kinsa spotted the falloff in fevers.

The Kinsa readings certainly look "like a way to prove that social distancing works," Dr. William Schaffner at Vanderbilt University tells the Times. "But it does shows that it takes the most restrictive measures to make a real difference." Kinsa data appears to show that social distancing is also reducing transmission of the seasonal flu.

"People need to know their sacrifices are helping," Kinsa founder Inder Singh tells the Times. "I've had friends text or call and say: 'Inder, this seems overblown. I'm sitting at home by myself, I don't know anyone who's sick, why am I doing this?'" Read more about the fever mapping at The New York Times. Peter Weber