>> Welcome back everyone to Inside Infection Control, our video series here at CDC's Project Firstline. I'm Abby Carlson. I'm an infectious diseases doctor at the CDC, and it's wonderful to have you here today with us. We talked in an earlier episode about what ventilation is, the movement of air in and out of spaces. But now let's talk about why it matters and what you can do about it. Let's talk first about air in healthcare. Having clean air in healthcare can help reduce the risk of germs, particularly that of COVID-19, from spreading among patients and among your co-workers. You may not know this unless you're part of your maintenance staff or you work on air systems in your building but nearly every room in a healthcare facility has a recommended number of air exchanges. An air exchange is the time that it takes for a room's old air to be completely replaced or nearly completely replaced with new air. We usually measure it by the hour. So we think about how many times per hour the air in the room is replaced. It's complicated and it's a lot more than most of us need to be experts on. Even I have the basic principles and then I talk to the experts about a lot of the complex stuff. But it's important to know how often the air in that room is being exchanged or cleared and that will tell you how long the room should sit after a person leaves and before another person can come in without a respirator or other PPE. It's really important to note that we're talking about entering without PPE. You can enter the room with your PPE before the air has exchanged and, of course, while the patient is still in there. But without PPE, the wait time is important and that's something that we recommend to wait for before you go in. You could always talk to your building's engineering for maintenance staff to find out more or the people who deal with your heating and cooling systems. Even before COVID-19, these recommendations were in place for air exchanges because it's that important to make sure that air is reasonably clean and moves in and out of rooms. One good way to check if there is ventilation of any sort happening is to look for vents and fans just like you would in a house where heating -- see where heating and cooling is coming from. There are some simple things that you could also do to increase ventilation. So for example, if somebody is microwaving fish in the break room, what do you do? Well, you open a window. You turn on a fan. Or you avoid the area until the smell has gone away, the air has been exchanged. But in healthcare, things like opening a window or changing the fan in the room can change the balance of air across a lot of different spaces. So one room is affected by another is affected by another and that's why it's important to work with the people at your facility who are in charge of air handling and ventilation and not to do things on your own so that you don't affect air movement in the wrong way. So ventilation is important in healthcare, and it's one of many strategies for keeping germs from spreading. And you should use it as much as you can to keep that air clean. Thanks again, as always, for joining us. Please be sure to follow up on Facebook, on Twitter, on YouTube, and check us out on the website at cdc.gov/projectfirstline. We will see everyone back here with the next episode.