Mask of the mind

Planning your breaths could save your life

Gareth Idris
3 min readJan 14, 2021
Chief Wiggum backs away screaming and shooting at a virus (The Simpsons).
Chief Wiggum has made some tactical errors here. Let’s investigate!

When someone with Covid breathes out, viral particles are most concentrated right next to their nose or mouth. The further away from them, the more diffuse the virus is — that’s why we socially distance.

You can imagine the viral particles in the air, in a dense cloud directly in front of people’s faces, and the cloud becoming more sparse, as it spreads out.

Intuitively, breathing closer to someone is worse than breathing further away from them, because you’ll be breathing in more virus than if you’d taken that breath at a greater distance.

The amount of virus you breathe in, and how long it’s within you, matters — the more virus, the higher the chances of infection being able to take hold.

So, what are the most protective ways we can breathe when we’re near other people?

  1. Holding your breath. The virus literally cannot enter (or exit) your lungs. Of course, it’s hard to do this for long.
  2. Gently breathing out. You might still feel the need to breathe, but breathing out is better than breathing in, because again, the virus can’t get into you if you’re not breathing in. You want to breathe out as slowly as possible, because you could be infected, and you don’t want to be breathing out a lot of virus while you’re near others.
  3. Gently breathing out and in. Often you’re close to people for too long to only hold your breath or exhale — in this case, shallow breathing will minimize the amount of virus you can breathe in.

How can we use this knowledge to reduce the spread of infection? Here are some examples:

Breathe out gently or hold your breath as you’re passing by near people.

  • Move into more open spaces before you take a large breath in.
  • Take a breath outside an elevator, and hold your breath or only breathe very gently while inside.
  • Don’t exhale strongly or sigh heavily when you’re close to people, as you yourself could be infected, but have little to no symptoms.
  • If you’re standing in a socially distanced line, or need to move into a space where someone just was, wait a few moments for the air to disperse before stepping forward.
  • If you’re walking to the bathroom in a bar or restaurant, hold your breath or minimize your breathing as you pass other groups. If your mask is off, you might press a napkin against your nose and mouth.
  • Moving quickly means you’ll breathe more heavily. Slow down to a casual stroll as you approach a shared space, and give yourself a chance to slow your breathing.
  • Remember that talking loudly also means expelling air from your lungs.

Don’t sweat it if you find these difficult at first. It takes everyone a little getting used to, and it can be difficult to hold your breath for tens of seconds without some practice.

The best part is, these skills work as an additional safety measure with other techniques — masks, vaccines, social distancing, and so on. But they also work when not wearing a mask, when vaccines are limited, and in cramped spaces, like elevators and hallways, where social distancing isn’t possible and airflow is limited. You can always wear the mask of the mind.

We can develop these skills and our understanding together to help stop the spread of the virus.

Remember to follow the latest CDC guidelines on mask fit, or wear an N95 mask if you can.

If you’re interested in a deeper look, see this article on the scientific understanding that underpins these ideas.

This work is licensed under a Creative Commons Attribution 4.0 International License.



Gareth Idris

Systems Engineer in Site Reliability Engineering at Google. Degrees in Biomedical Science and Electrical and Computer Systems Engineering.