U.S. airlines now require customers to wear face masks on board their flights. The last major holdout, Allegiant Airlines, has changed course and follows this practice. Delta Air Lines will now require passengers who seek an exemption to have a medical consultation when they arrive at the airport.

Many airports already require face masks, but United is imposing the requirement now at airports themselves starting this Friday, July 24. They’re putting the same teeth of a potential travel ban in place for customers not wearing masks in areas of the terminal that they control.

• customer service counters and kiosks
  
• United Clubs (that are open)
  
• gates and baggage claim areas

United may need to enforce a more robust mask policy, considering that – unlike Delta, Southwest, JetBlue and Alaska – they’re selling all the seats on planes rather than limiting capacity so that middle seats can remain open.

The airline will also be requiring that masks be worn by all children two years old and older. Masks are medically not recommended for children younger than that, though as the father of a girl who is almost two it seems like it would be hard to get her to keep the mask on her face throughout the course of an entire trip from arrival at the terminal to exit on the other end of the journey. (For what it’s worth my wife thinks she’d keep it on if it’s a game.) There’s significant evidence that very young children do not spread Covid-19 nearly as much as older children and adults.

United now refers to exceptions to their mask policy as “extraordinary circumstances” that customers should discuss with the airline specifically. They aren’t going as far as Delta in requiring a medical consult – which would cost them money.

Uber requires face masks. Marriott hotels now require customers to wear face masks indoors worldwide, and Hyatt requires it in the U.S. and Canada. So when you leave the airport you may need to wear a face mask too.