We all do whatever it takes to comfort a loved one who is ill. And while such selfless behaviour is what keeps families and friends together, the COVID-19 pandemic has made it necessary to be cautious even while taking care of a loved one who has contracted the virus. So, here are a few simple techniques that can protect you, or other family members and people coming in contact with a COVID-19 patient.

It is important to understand the ‘why’ before we move on to the ‘how’ — how you can have a safer home where chances of disease spread can be minimized.
Let’s say a person named Ravi is COVID-19 positive and has high fever. Ravi’s parents will of course wish to apply wet cloth compress to bring down the fever, no matter how many times he asks them not to do so.
With the passage of time, the number of virus particles in the air in his room is only going to increase, because with every breath Ravi emits fine water droplets that carry the coronavirus. Even if Ravi’s parents are wearing PPE and masks while treating him, the chances of transmission will become progressively higher. Also, depending on how air flows inside his home, viral particles might enter other rooms as well and end up infecting others, even if they are not in direct contact with Ravi.

Now, here’s what Ravi does to minimise those chances. In order to protect others, he changes the room arrangement as shown below and only allows his parents to sit on the blue chair (with masks and protective gear) and no one can sit on the red chair.

What he did is quite simple, but definitely effective. He has placed a table-fan which is facing an open or partially open window. While sitting on the blue chair the chances of virus-laden water droplets interacting with his parents will be less, because the viral particles will follow the path of the blue arrows and will exit the room. Also, the chances of viral particles drifting away to the other rooms is also minimized now.
It should be noted that he is not allowing his parents to sit on the red chair because the possibility of viral particle interaction for someone sitting on the red chair will be much higher.
In a nutshell, we can drive the viral particles out of the room using a simple fan and a window.
We should try to imagine the flow of air and always remain upstream, that is:
You → person with COVID-19 → Fan → Window
Always avoid being downstream i.e.
Person with COVID-19 → You → Fan → Window
This is how you can make the best possible configuration to protect yourself, other family members and at the same time take care of your loved one with COVID-19.
I have personally been going outside for work and using these simple techniques to protect my family. For example, I always sit beside an open door. Now someone might ask, what if air comes into the room? Then, you would be exposing your family to the viral particles that you may have exhaled.
However that’s not the case, let’s try to understand why. If I inhale one SARS-CoV-2 virus, I won’t test positive for COVID-19. I should have inhaled at least a few thousand active viruses within a short span of time for me to be COVID positive. Now, as the air moves inside, the viral particles from my breath (assuming I am COVID-19 positive) will be diluted by a simple process of diffusion. By the same process as takes place when someone smokes a cigarette. It gets diluted after a few centimetres, so that you can no longer see the smoke even if you can smell it.
Therefore, by the time the contaminated air with viral particles reaches any of my family members, due to diffusion the concentration would be much less and the chances of inhaling enough viral particles at once will be much less too.
However, having noted all of the above, it must not be forgotten that there is heterogeneity in our immune responses to the coronavirus. Disease severity and susceptibility to the infection are also dependent on co-morbidities. At the end of the day, a person with mild or asymptomatic infection must also isolate himself, even at home. Without discounting any of these, the above steps outline the best course of action if we want to reduce the possibility of air-borne transmission within our houses.
[A shorter version of this post was first published here and has been republished with permission.]