Athletes and others headed to the Olympics face a multitude of COVID-19 testing hurdles as organizers seek to catch any infections early and keep the virus at bay.

A positive test could mean athletes sitting out the Beijing Games — perhaps even if they’re no longer contagious. Olympic officials say they’ll be flexible and review the need for isolation on a case-by-case basis.

It’s part of the complexities of staging a big event in the pandemic, because organizers want to ensure they don’t fuel outbreaks among participants or the local population. Since early in the pandemic, China has taken a “zero tolerance” approach to the virus.

Similar protocols to create virus-free “bubbles” were part of the Tokyo Games last summer and the end of the 2020 NBA season.

Here’s how testing will work at the Winter Olympics:

WHAT WILL TESTING BE LIKE?

All athletes, team officials, staff and journalists need to provide two recent negative tests before heading to China. They will be tested again at the airport before heading to their Olympic sites. During the Games, everyone will get daily throat swabs for PCR lab tests, with results coming back within a day.

And most everyone will already be vaccinated, because those who aren’t have to quarantine for three weeks.