John F. Kennedy International Airport in New York began its enhanced Ebola virus disease screening process Saturday, Reuters reported. JFK airport is the first of five U.S. airports to start implementing the policy, which includes questionnaires and thermal scanners to monitor elevated temperatures. Screenings will be conducted by the federal Department of Homeland Security’s Customs and Border Protection agency under the supervision of the Centers for Disease Control and Prevention.

There are about 150 travelers inbound from Guinea, Liberia and Sierra Leone to the U.S. daily, and close to one-half of them arrive at JFK airport, CDC representative Jason McDonald told Reuters. These travelers have already been screened at their outbound airports.

The screenings include questions about the health of a passenger and whether the individual has been in contact with an Ebola patient. If anyone displays signs of potential sickness or an elevated temperature, he or she will be referred to a CDC official who will determine whether the traveler needs further testing at a nearby hospital or quarantining under federal law.

U.S. laws allow for the quarantine of individuals who could potentially spread infectious diseases, such as smallpox. The CDC has 20 quarantine facilities that could house travelers for three weeks, the incubation period for Ebola virus disease. Some experts are questioning the effectiveness of the Ebola screening policy, saying travelers could lie or take medicine to reduce fever, Reuters reported. “People may not fill them in very truthfully. They don’t want to be delayed for hour,” said David Mabey, a professor at the London School of Hygiene and Tropical Medicine. Other experts said there could be an educational value for travelers as early detection of Ebola increases the chances for survival.

The four other airports to enhance screening of travelers for Ebola are O’Hare International in Chicago; Hartsfield-Jackson International in Atlanta; Washington Dulles International in Dulles, Va.; and Newark Liberty International in Newark, N.J. Implementation of the policy will be rolled out in the coming week.