How do the different types of masks work?

Medical masks

Also called surgical masks, these are loosefitting disposable masks. They're meant to protect the wearer from contact with droplets and sprays that may contain germs. A medical mask also filters out large particles in the air when the wearer breathes in.

To make medical masks more form-fitting, knot the ear loops where they attach to the mask. Then fold and tuck the loose material under the edges.

Wearing a medical mask doesn't increase the level of carbon dioxide in the air you breathe.