Having a fever above 100.4 degrees Fahrenheit and recently visiting Toronto could get you booted from Carnival Cruise Lines and Royal Caribbean Cruises under a new policy intended to stem the spread of SARS (search).

Both cruise lines said Friday they would send home anyone who had been in Canada's largest city in the past two weeks and had a fever or showed other symptoms of severe acute respiratory syndrome.

"It's a great thing," said Sonia Rodriguez, a 46-year-old physical therapist from Fort Lauderdale who was boarding a cruise for the Bahamas on Friday. "It's needed, especially in a place where you're contained with thousands of people in the dining room or the pool and places like that."

The cruise lines already had banned passengers who had recently traveled to China (search), Singapore, Hong Kong or Vietnam. Toronto was included after the World Health Organization (search) this week added the city to a list of places travelers should avoid because they are hot spots for SARS.

The disease has infected 4,600 people and killed more than 270 since it was identified in Asia months ago. Most of the 18 deaths in Canada were in Toronto. No one in the United States has died.

Royal Caribbean kept six passengers off a cruise about two weeks ago because travelers in the two groups had been in Asia, company spokesman Michael Sheehan said.

Carnival spokeswoman Jennifer de la Cruz said she didn't know if anyone with Toronto ties has been denied boarding as of Friday. Carnival is the world's No. 1 cruise operator, followed by Royal Caribbean.

Carnival and Royal Caribbean are offering full refunds or credits for future voyages for passengers they turn away, plus reimbursement of any air travel costs.

The Canadian Consulate in Miami cautioned the Miami-based cruise lines against overreacting to the situation in Toronto.

"This thing can be blown out of all proportion, so we have to be careful," said Consul Tony Knill. "People who have the disease have been isolated, there have been no new cases in over a week, and the situation is very stable. As long as it is under control, then there shouldn't be the concern."

Cruise lines late last year had to take precautions to handle about 1,500 passenger illnesses caused by the Norwalk virus. Some ships were removed from service and voyages canceled so the ships could be thoroughly cleaned.

Norwalk-like viruses cause diarrhea, stomach pain and vomiting for up to 48 hours.