Don't shake hands, don't kiss on the cheeks, don't go to the movies -- best of all, just stay at home.
That is the advice citizens of Mexico City are getting from their government as it struggles to contain a deadly outbreak of swine flu that has already sickened more than 1,000 people and killed as many as 68.
The deaths contrast with several swine flu cases in the United States, which so far generally have seemed milder.
On Friday, the government closed all schools and colleges in this city of 20 million people, as well as museums and concert halls. All public events have been cancelled for at least the next 10 days.
The streets of the capital are relatively empty. Public parks that would normally be crowded on a weekend look almost deserted, and the buses and subways are running with very few passengers on board.
Many of those people who do venture out onto the streets are wearing blue surgical face masks, which, it is hoped, can reduce the chances of infection.
Pharmacies are selling the masks for 10 cents apiece, and in some locations in the city center soldiers on military trucks are handing out the masks for free.
The World Health Organization is closely monitoring the outbreak in Mexico, and has already identified the virus as a strain that partially originated in pigs.
But the virus is now being passed between people who have had no contact with pigs, heightening fears that this could become a pandemic.
Regular flu vaccines do not appear to be effective against this new strain of the virus, but the Mexican government has stockpiled one million doses of anti-flu medication that can be used to treat people once they come down with the disease.