The speed with which patients deteriorate and die from the novel coronavirus is shocking even veteran doctors and nurses as they scramble to work out how to save patients.

They “look fine, feel fine, then you turn around and they’re unresponsive,” said Diana Torres, a nurse at Mount Sinai Hospital in New York, NY, the epicenter of the US pandemic.

“I’m paranoid, scared to walk out of their room.”

It isn’t just elderly patients or those with underlying health conditions who can be fine one minute and at death’s door the next.