When the government appealed recently for 250,000 people to help the National Health Service, more than 750,000 signed up. It was forced to temporarily stop taking applicants so it could process the flood. In addition to the national program, hundreds of community-based aid groups have sprung up around the country, enrolling tens of thousands of volunteers.

The lockdown, Mr. Goodhart said, has exposed the “hidden indoor plumbing” of an affluent society: garbage collectors, delivery people, drugstore clerks and grocery store workers who keep food on the shelves. “It turns out that shelf stackers in supermarkets are absolutely vital,” he said.

Most poignantly, it has exposed the plight of seniors, who run by far the highest risk of succumbing to the pathogen.

“The government has told 1.5 million people to stay inside, without any idea of who they are or how they’re supposed to do that,” said Connor Rochford, a medical doctor and former management consultant who started Hampstead Volunteer Corps with his partner, Sarah Dobbie, and another couple, Kate and Brendan Guy.

Read more in the New York Times.