Norwegian Cruise Line managers urged their sales teams to share false information about the novel coronavirus to help land bookings with potential customers, including that the virus can’t affect people in “tropical temperatures,” leaked emails from a company whistleblower show.

The emails, first reported by Miami New Times, show the lengths to which the U.S. cruise giant’s leaders have gone to protect the company against the devastating financial impact of the pandemic, which has infected more than 121,000 people around the world and killed more than 4,300.

The State Department has warned travelers against taking cruises during the pandemic, and U.S. health officials have prevented some ships from sailing. Cruise lines are expected to lose hundreds of millions of dollars this year because of mass cancellations and a slowing of new trips.

Norwegian Cruise Line’s stock plunged 26 percent Wednesday and has fallen nearly 75 percent from its January peak. The company did not respond to requests for comment.

In emails the whistleblower shared with The Washington Post, salespeople were given a list of one-liners to help “close your guests that are on the fence,” including that virus-related cancellations in Asia have “caused a huge surge in demand” for other trips.

The recommended lines, written last month by a manager whose LinkedIn profile suggests the person has worked at the company for more than eight years, also compared the number of confirmed cases of the coronavirus with the flu and said, falsely, that the virus “cannot live in the amazingly warm and tropical temperatures that your cruise will be sailing to.”

“The only thing you need to worry about for your cruise is do you have enough sunscreen?” the manager wrote in an email addressed to dozens employees in two sales offices in Florida.

The whistleblower, an employee in South Florida who declined to be named for fear of retaliation, said several dozen people on the sales team have been instructed to call more than 150 people a day in pursuit of cruise bookings.

“That means hundreds or thousands of people on a daily basis are potentially getting this false information,” the whistleblower said. “This is what they’re expecting everyone on our sales team to be saying to all of our customers.”

Employees were also urged to tell customers that scientists and “medical professionals have confirmed that the warm weather of the spring will be the end of the Coronavirus,” the emails show. But that assertion is contradicted by early scientific evidence, which suggests that the novel coronavirus can spread easily across a wide range of communities, including in warm and humid climates.

“Certainly out here in Singapore, it transmits without any problem,” David Heymann, a professor at the London School of Hygiene and Tropical Medicine, said in an interview. Singapore’s government has recently implemented strict policies, including social distancing, to stem the outbreak, with apparent success.

Epidemiologists and health experts also suspect that the virus’s spread could continue for months. Jeffrey Shaman, the director of the climate and health program at Columbia University’s Mailman School of Public Health, said there has been no clear evidence to suggest that the coronavirus that causes the covid-19 disease is less transmissible at higher temperatures. The ongoing pandemic, he said, could last straight through the summer in the United States and Europe.

Large groups of people in close quarters for extended periods, such as on cruise ships, could lead to continued transmission, health experts said. The Grand Princess, a ship owned by Princess Cruises that docked in Oakland, Calif., on Monday, had more than 3,000 people aboard who were potentially exposed to the virus and were expected to be quarantined.

Some of the sales managers’ messages echo those of President Trump, who has been criticized for saying that the coronavirus “dies with the hotter weather” and “is very much under control” in the United States.

In the email of one-liners, sales representatives were told to “NOT USE THESE unless the coronavirus is brought up.” But the whistleblower said the virus is callers’ top concern: “Every single call we’re getting right now is about the virus. Everyone wants to know what’s going on, what’s happening to the ships. Most people just want to cancel.”

Cruise lines have faced an onslaught of passenger concerns over the safety of upcoming trips. Chris Chiames, a spokesman for Carnival Cruise Line, said the company has expanded its customer cancellation policies and provided employees “with clear guidance on working with our guests in a positive and constructive manner.”

In another leaked Norwegian Cruise Line email, another sales manager based at the company’s Miami office suggested that “medical fear stories” were being exaggerated to make “more moola for the fat cats at major media houses.”

“Focusing all of your attention is actually illogical, especially when we live in a world of daily threats and dangers anyhow,” the manager wrote under the headline “The coronavirus will not affect you.” “Fact: Coronavirus in humans is an overhyped pandemic scare.”

The whistleblower told The Post that company leaders are trying to find out who shared the emails. In one email sent Monday evening, after a Miami New Times journalist contacted the company, an executive wrote, “One of our own ratted.”

Andrew Freedman contributed to this report.