Most airlines won’t pay cash to refund a flight if you decide to heed national health warnings but they are waiving fees and offering vouchers. Breyault said to “familiarize yourself with the policies” because the voucher specifics vary by airline and can depend on when the ticket was booked.

It’s not clear how many people are taking those vouchers. Images that emerged this weekend of crowded airport terminals showed that plenty of people are flying anyway.

On Sunday, 1,047,934 people were screened at U.S. airports, the highest number of passengers boarding flights in a single day since March 16, according to the Transportation Security Administration. In all, over three million people were screened over the weekend. While that’s far lower than during the same time last year, Friday also marked only the second time since mid-March that daily airport screenings topped 1 million.