DENVER -- On the flight from Mexico City to Denver this afternoon, some passengers took precautions against swine flu.

“I wore my mask, but don’t worry I don’t have swine flu,” said Alberto Morales, who had just arrived in Colorado for a business trip.

Other passengers took it in stride.

“There’s always an overhype of things like this so I wasn’t that concerned,” said Melanie Holzner. “I mean I have a little throat scratch ... Just kidding I’m fine.”

Holzner and her husband, Kim, will be on vacation longer than planned, though, since his employer asked him not to come to work tomorrow.

“Just to make sure if we have got anything ... it takes one day to see if we’re going to be sick,” said Kim Holzer.

Denver International Airport has taken steps to address the swine flu scare.

Chuck Cannon, an airport spokesman, said if someone shows symptoms of swine flu on a flight, the plan will be held away from the gate while paramedics check out the sick passenger.

The other passengers will be allowed to leave, he said.

The CDC has already said swine flu cannot be stopped at the border; it’s already in the United States.

The public health focus is now slowing the spread of the virus, in part, by encouraging hand washing, staying home if sick and avoiding people who are sick.

Mexico-bound travelers stocked up on surgical masks and hand sanitizer before leaving. Many said they wouldn't change their plans despite a U.S. government travel advisory because of swine flu.

"A hundred people a day probably die in Mexico City in car wrecks," said Jeff Henderson, 39, who was headed to a friend's wedding in Mexico. "It's just playing the odds, really."

More than 1,600 cases of swine flu have been reported in Mexico, and the suspected death toll is nearly 150. The U.S. Centers of Disease Control and Prevention said an advisory was being prepared suggesting Americans avoid nonessential travel to Mexico.

Megan Tschopp, 28, and Isabel Hedges, 25, both of Jackson, Wyo., were flying from Denver to Guatemala for a six-week Spanish course with a stopover in Mexico City. They picked up surgical masks on their way to the airport and then turned off their cell phones so they wouldn't get flooded with calls from worried relatives.

"I mean, there's nothing they can do," Tschopp said.

No swine flu deaths have been reported in the U.S, and only one hospitalization.

Lori Maldonado of the Colorado Department of Public Health and Environment said no swine flu cases had been reported in Colorado.

The state health department opened its emergency operations center and set up a phone line (877-462-2911) to answer questions. The state also asked the federal government for antiviral drugs and masks as a precaution.

The U.S. stepped up checks of people entering the country by air, land and sea, but Denver International Airport officials said they were taking only normal precautions.

Transportation Security Administration workers in Denver were allowed to wear gloves and masks but weren't required to, airport spokesman Jeff Green said.

Green said the airport had its normal contingent of paramedics on duty but no extra staff. If an incoming flight crew noticed passengers with symptoms, a paramedic would board the plane to check, but that's normal procedure, he said.

Travelers arriving in Denver from Mexico City shrugged off concerns and said they had faith the Mexican government is doing everything possible to prevent the spread of swine flu.

"There's no panic, people are doing the things they normally do without fear and just paying attention to the news," said Arturo Bermudez, 81, a Denver resident who returned to Colorado after visiting relatives in Mexico City. He stepped off the plane with a surgical mask wrapped around his neck.

Alberto Morales, a Mexico City resident on a weeklong business trip to Denver, said about half the people on the plane were wearing masks. He also said he wasn't worried about the swine flu because "we're informed about it, there's medicine, and there's a cure for the illness."

"I think our government is managing things well," he said.

Denver Public Schools reminded teachers and students to wash their hands and take other normal precautions but didn't plan any extra scrubbing.

The Mesa County School District in western Colorado said it planned no extra cleaning and that the county health department was handling advisories on prevention.

Jefferson County Public Schools, the state's largest district, said it was taking normal precautions but nothing extra.