COVID-19

Infection is not inevitable: how to stop the spread of infections like COVID-19, flu, RSV, colds, and more in your house

by Dana Lewis

I observe a number of people who seem to think it’s inevitable that once someone gets sick, the rest of the house is going to get sick with 100% certainty.

Nope.

First of all, household transmission rates are less than 100% for all of these conditions, even if you didn’t take any precautions or make any behavior changes.

Secondly, with knowledge about how these things spread and some mitigation measures, you can reduce this a lot – and in some cases to nearly zero.

I will caveat: that of course depending on the situation some of these precautions may not make sense or be possible. For example, if you have kids, your exposures may be different. We don’t have kids in our house, so we are dealing with adult to adult possible transmission. That being said, some of these things may still be worth doing to some degree, to cut down the risk of exposure and/or to limit the viral dose you are exposed to, even in a situation that is less straightforward like a parent taking care of sick kids.

PS – if you’re reading this in January 2025 and don’t read the rest, make sure you’ve gotten your flu shot (yes, it helps) for the 2024-2025 flu season. No, it’s not too late. If you’re >65, you should also check about the RSV vaccine (which like the flu shot is a seasonal vaccine). It’s not too late and given the current high rates of RSV and flu (and soon to be uptick in COVID), they can help prevent getting or limit the severity if you do get exposed.

Our experience preventing the spread of RSV and the common cold

I can speak with recent, practical experience on this.

Twice.

First, let’s talk about RSV.

Before Thanksgiving, Scott and I were exposed to a nibling (aka a niece or nephew – of which we have 10 plus several honorary ones!) who had what we thought was a lingering cough from a cold from a few weeks ago. Because I am avoiding infection, I wore a mask inside and did not get up close to the nibling, so as a result of all of this likely had minimal exposure. Scott did not mask and had spent a lot more time with this nibling hanging all over him and coughing near or on him. Within 48 hours, he started to get symptoms of something.

We activated our plan for household transmission avoidance. Well, with a rolling start: Scott recognized by Thanksgiving evening that he was starting to feel unwell and had a tiny bit of coughing. I thought I could hear something in his chest differently, in addition to the occasional cough, so I went into full precaution mode while Scott did a partial precaution mode. This meant we set up air purifiers by each of our beds, and a fan pointed in my direction so all air was blowing away from me. I also wore a mask to go to sleep in. (This was super annoying and I don’t like doing this, especially because I usually take a shower and go to bed with wet hair. Wearing an n95 with head straps on wet hair plus having a fan and purifier blowing on me is chilly and unfun.) I would’ve preferred Scott to mask, too, or go to the guest bedroom to sleep, but it was late in the evening; he wasn’t convinced he was really sick; and I was too exhausted to argue about it on top of the fact that we were leaving on a trip the next morning. So he did not mask that night.

The next morning, though, he was definitely sick. He tested negative for COVID, and the nibling and everyone else from that house had been testing for COVID and negative, so we were fairly confident based on serial testing that this was not COVID. At the time, the thought was this was a common cold.

Since we were planning to mask in indoor spaces, anyway, including in the airport and on the plane, we felt comfortable going on our trip as planned, because we would be unlikely to infect anyone else. (This includes no indoor dining: we don’t take off our masks and eat inside.)

Because Scott realized he was sick, he masked from that point forward (with a non-valved N95). We both masked in the car, in the airport, on the plane, and again when we arrived while driving in the rental car. Then a challenge: we needed to eat dinner (we got takeout), and we were sharing a hotel room overnight. We switched from a hotel room with a king bed to a room with two queen beds, which would give us some more space overnight. But we took turns eating dinner unmasked in the hotel room (it was too cold to be outside) with the far-UVC lights on and the purifiers around each of us when we ate. While we ate, the other person was masked. (And I went first, so there was no unmasked air from Scott while I was eating and he went second). We also took turns showering, again with me going first and him not having been in the bathroom unmasked until after I had gone in. Other than that, we stayed masked in the hotel room including overnight, again with purifiers between us and the far-UVC lights running.

(This hotel did not have windows that opened to outside, but if there had been windows I would’ve eaten in front of the open window and we would’ve likely kept it cracked open and the heat turned up, to improve the room’s ventilation).

The next day, we had more of a drive, and again we masked. We also slightly rolled down the windows in the backseat to improve ventilation. Scott sometimes took his mask off for comfort stretches, because he was driving, but put it back on fully and sealed it before coughing. I kept my mask on without ceasing. We did a 4.5 hour drive this way.

Luckily, once we arrived at our destination, there was a spare bedroom, so that became Scott’s headquarters. He stayed masked in the living room/shared areas. He sat downwind outside and masked up when coughing if anyone was outside. We left the sliding door to the outside cracked open, in order to keep the air in the common areas well-ventilated. This worked, because we were able to keep CO2 levels (a proxy for ventilation) down below 700 ppm most of the time.

Because we had separate bedrooms, we did not mask while sleeping the rest of the week, because we each had our own rooms (and own airflow). I did keep a purifier running in my room all week, but that’s my habit regardless because I’m so allergic to dust.

And guess what? It all worked. We masked again on the drive back to the airport and in the airport and on the plane and again once we got home.

I never got RSV. The four other adults we spent time with and shared a house with….also did not get RSV. So we are pretty confident that the transmission chain stopped completely at Scott.

In summary, what worked:

  • Masking in shared spaces, and two-way masking when it wasn’t possible to ventilate
  • When we had to sleep in the same room, two-way masking even for sleeping overnight
  • Scott masking in shared spaces that were well ventilated, and often left the room to go cough even when masked (or coughing outside). This often meant he masked, but the rest of us did not mask inside the whole time.
  • Generally keeping distance. Droplets were managed by the N95 mask, and we were ventilating to reduce aerosol transmission risk, but still keeping physical distance to further reduce the risk.

RSV is *very* transmissible especially with aerosols, and Scott was coughing a lot all day and night. (At one point, his Sleep Cycle app was estimating 18 coughs per hour). It took a long time for that to get down to normal, so he continued to sleep in our guest room when we got back and we continued to ventilate well even when we gradually reduced masking once he stopped coughing. It took about 10 or so days for all of his biometrics to normalize, and about 14 days for his cough to completely go away. It probably was closer to three weeks before he finally felt all recovered.

So with that timing in mind, you know what happens 4 weeks after Thanksgiving? Christmas/other end of year holiday gatherings.

We had plans to see 8 kids and 8 adults (plus us) for Christmas. And at Christmas, it seemed like everyone had a cold already. So again, I went in and mostly masked except for when I was in front of an open window and the room was well ventilated, without anyone coughing actively in the room. (If anyone was in the room with me and coughing, especially the kids, I would mask even with the window open).

I did not get the cold that 8-10 (out of 16) people eventually got.

But…Scott did. And this time, he was mostly masked, but he still spent more time up close with kids who were coughing quite a bit. And this is where some of the dynamics of knowing WHAT people have is helpful. You can’t always know, but you can sometimes use the symptoms to figure out what people have.

For example, based on symptoms of the nibling who passed on germs to Scott around Thanksgiving, and Scott’s symptoms (instant, incredible chest cough but no runny nose, sore throat, fever, or aches) we had ultimately guessed that Scott had RSV. We then knew that the biggest risk was either droplets from coughing (especially because the volume of coughing), which could be reduced drastically by masking, or aerosols, which again would be helped by his masking and also ventilation, and in closed spaces, two-way masking (me masking).

For the Christmas germs, everyone seemed to have mild symptoms with congestion, runny noses, some coughs. But no fevers or aches and it seemed less severe. Given our recent experience with RSV, we narrowed it down to likely being a cold (rhinovirus), given again everyone testing repeatedly negative for COVID.

Given that, we knew the risk was going to be highest for us from droplets and fomites. So we again masked in shared spaces; Scott went to sleep in the guest bedroom as soon as he started getting symptoms; and we both did a lot of hand washing. Scott washed his hands before touching any of my things and regularly wiped down the kitchen. I tried not to go in the kitchen much (our main overlapping shared space), but also wash my hands after any time that I did. He didn’t have much of a cough and it was more controlled, so he would hold his cough until he could cover it with a mask or be in the room by himself. We also did our usual running of purifiers and opened windows and ran fans to increase ventilation to keep CO2 low.

And again? It worked. I did not get the cold, either from any of the ~8+ folks who did across the holiday period, or from Scott. Scott’s vitals all returned to normal at the five day mark, although we continued to mask in the car through day 7, to be more cautious (due to my personal situation).

So, infection is not inevitable, even in small houses and apartments.

Here’s what we’ve taken away from these experiences with more aerosol-based (RSV) transmission diseases and more droplet and fomite-based (cold) experiences:

  1. Two-way N95 masking works. Mask in the car, run the fan, keep the windows cracked, run purifiers at home, and ventilate spaces, but you still want two-way masking when something is aerosolized and you’re in the same spaces. This can prevent transmission.
  2. Keep distance when someone is coughing and sneezing (and if they have a cough or sneeze type illness, you want 6 foot distance even when they’re not actively coughing or sneezing, because they make droplets just from breathing and talking). The person who’s coughing and sneezing should mask, even inside, unless they are in their own room in private (and it’s not a shared room).Keep your air ventilated (if you haven’t, read my post about ventilation and using a Co2 monitor)Depending on the illness, to fully protect yourself you’ll need to commit to wearing a mask at all times indoors to protect yourself if the person who is sick is not masking. (Eg, Scott got a cold while mostly masked around heavily coughing niblings, but not throughout the whole house the whole day). With adults, the adults who are sick should definitely mask if they’re in shared spaces with other adults. (It’s harder with kids, and it should be a conversation depending on the age of the kids about them masking in shared spaces, such as if they want to play with Uncle Scott, or help them understand that someone may not want to play up close if they’re sick and coughing and not willing to mask. That’s fine, but that’s a choice they can make when kids are old enough to understand.)
  3. Have the infected person sleep in a different space (on the couch or in another room if you have a spare bedroom). If you have to share a room, both should mask.
  4. Use cleaning wipes to wipe down shared surfaces (e.g. fridge handles, microwave, counters, bathroom surfaces like the flush on the toilet or sink faucet, etc) and wash your hands after using these shared spaces every time. Fomites can last longer than you’d expect.
  5. Use metrics from your wearable devices (eg Apple Watch or Oura ring or similar) to track when your temperature, respiratory rate, heart rate, cough rate, etc. return to normal. That tied with symptom elimination can help you determine how long you’re likely most infectious for. The general estimates of contagiousness for each condition generally seem to be right (e.g., two weeks for an adult with RSV and 5-7 days for a cold) in our recent experiences. I would continue precautions for at least those minimum time frames, if you can.
  6. Yes, there’s a cost to these precautions, in terms of human contact. There was no hugging or hand holding or kissing or any touch contact during these time periods. I felt pretty lonely, especially because it was me we were trying to protect (because I am at high risk for bad outcomes due to immunosuppression right now), and I’m sure Scott also felt lonely and isolated. That part sucked, but we at least knew it was a fixed period of time, which helped.

What we’d do differently next time

Infection is not inevitable -how to reduce transmission of illness in your household (including COVID-19, RSV, flu, and the common cold), written by Dana M. Lewis from DIYPS.orgThis basically has been our plan for if either of us were to get COVID-19 (or the flu), and it’s good to know this plan works for a variety of conditions including RSV and the common cold. The main thing we would do differently in the future is that Scott should have masked the very first night he had symptoms of RSV, and he has decided that he’ll be masking any time he’s in the same room as someone who’s been coughing, as that’s considerably less annoying than being sick. (He really did not like the experience of having RSV.) I obviously did not get it from that first night when he first had the most minor symptoms of RSV, but that was probably the period of highest risk of transmission of either week, given the subsequent precautions we took after that.

Combined, everything we did worked, and we’ll do it again when we need to in the future, which should not be very often. We went five full years without either of us getting any type of infection (yay), and hopefully that continues from here on out. We’ll also continue to get regular COVID-19 boosters; annual flu shots; and other annual shots if/when they become available (e.g. when we reach the age, getting the RSV vaccine).

—

Remember, if you’re reading this in January 2025, RSV and flu levels are very high in the US right now, with COVID-19 expected to pick up again soon. It’s not too late to get your boosters and given the rates of respiratory illness, consider situational masking even if you don’t typically mask.

Peer pressure during and “after” the COVID-19 pandemic, why it’s similar to living with celiac disease or food allergies, and a reminder that we usually have choices

by Dana Lewis

Imagine that you are invited to go out to eat with a group of friends, or with colleagues at a conference.

Your mind races.

You start to think through the venue and if it’s safe for you to go. What the experience will be like at the venue. What the short-term risks are over the next few days. What the long-term risks are for you and your health, because what you choose to do will potentially influence your health for years to come.

Maybe you shouldn’t, or don’t want to go.

Given the venue, you realize that you can make choices for yourself to make it safer for you, regardless of what anyone else does. You can choose to go, but you can also do things differently than everyone else. But there’s a cost. There’s a short term cost of being the “different” one at the table.

So what do you choose? Do you cave to social pressure, and “just do what everyone else is doing”, because you think the risk of short term costs isn’t a big deal, and you don’t worry about the long-term costs to your health? Or do you decide to do something different, either not going, or doing something different at the venue than everyone else? Or do you decide to suggest an alternative?

—

For those of us who are reading this in 2022 or beyond, we may read the above scenario and think primarily about COVID-19 risk factors and mitigations.

But for those of us living with celiac disease (or food allergies or other significant dietary restrictions), the above scenario is one we lived with even prior to 2019 and COVID.

—

Here’s how this scenario could read specifically for COVID-19, with COVID-specifics bolded:

Imagine that you are invited to go out to eat with a group of friends, or with colleagues at a conference.

Your mind races.

You start to think through the venue and if it’s safe for you to go. What will the experience be like at the venue: Is it indoor or outdoor? What is the ventilation like? Is everyone in your group vaccinated and boosted? What the short-term risks are over the next few days: If you get COVID-19, how will that impact your schedule/life/childcare etc? How at risk are you for hospitalization with COVID-19? What the long-term risks are for you and your health, because what you choose to do will potentially influence your health for years to come: Are you concerned about “long COVID” or associated conditions? What are the risks that a COVID infection would make your personal health situation worse?

Maybe you shouldn’t, or don’t want to go.

Given the venue, you realize that you can make choices for yourself to make it safer for you, regardless of what anyone else does. You can choose to go, but you can also do things differently than everyone else. But there’s a cost. There’s a short term cost of being the “different” one at the table. You could go, but wear an N95 mask and only take off your mask to quickly eat or drink. Or you could go and mask, but not eat. Or you could bring a CO2 meter to evaluate the ventilation, and use that to decide.

So what do you choose? Do you cave to social pressure, and “just do what everyone else is doing”, because you think the risk of short term costs isn’t a big deal, and you don’t worry about the long-term costs to your health? Or do you decide to do something different, either not going, or doing something different (e.g. N95 masking, and/or not eating) at the venue than everyone else? Or do you decide to suggest an alternative, such as picking an outdoor venue instead of indoors, or choosing an activity that doesn’t involve close proximity and eating or drinking, such as a walk?

—

Now consider how this scenario could read specifically for someone with celiac disease (or food allergies or food restrictions), with those specifics bolded (in a pre-pandemic life):

Imagine that you are invited to go out to eat with a group of friends, or with colleagues at a conference.

Your mind races.

You start to think through the venue and if it’s safe for you to go. What will the experience be like at the venue: Do they have a gluten free menu? Do they indicate that they have cross-contamination practices in place for making the food gluten free? Does the menu even have food that is worth eating? What the short-term risks are over the next few days: If you get glutened and are someone who is symptomatic, how will the minutes, hours, and days following of not feeling well influence your schedule/life/childcare etc? What will you not be able to do because you won’t feel well enough? What the long-term risks are for you and your health, because what you choose to do will potentially influence your health for years to come: Some people with celiac disease aren’t symptomatic, but are causing damage even if they don’t feel it in the minutes/hours/days following. Eating gluten causes the immune system to attack the body, increasing the risk for cancer and other complications.

Maybe you shouldn’t, or don’t want to go.

Given the venue, you realize that you can make choices for yourself to make it safer for you, regardless of what anyone else does. You can choose to go, but you can also do things differently than everyone else. But there’s a cost. There’s a short term cost of being the “different” one at the table. You could go, but not eat if there’s not food worth eating or if you determine (in advance or at the restaurant) that they doesn’t have safe practices for preventing cross-contamination. You could go, but bring your own food and do your own thing.

So what do you choose? Do you cave to social pressure, and “just do what everyone else is doing”, because you think the risk of short term costs isn’t a big deal, and you don’t worry about the long-term costs to your health? Or do you decide to do something different, either not going, or doing something different (e.g. not eating, or bringing your own food) at the venue than everyone else? Or do you decide to suggest an alternative, such as recommending a different venue that has safer gluten free options, or choosing an activity that doesn’t involve eating, such as a walk?

—

In both a COVID-19 scenario and a scenario for someone with food allergies, food restrictions, or celiac disease, my point is that you have choices. While other people’s choices can affect you, your choices are the ones that matter most.

With celiac disease, which I’ve had for more than 13 years, I’ve personally chosen many times to not eat at places that weren’t safe for me.

I would eat a meal or snack before I go or while I’m there, or I bring food from elsewhere. Sometimes I’ve felt really awkward, but it was safer and the right choice for me to make. Sometimes it’s because I couldn’t change the venue, and the venue’s safe food was dry lettuce and dry chicken, and it just wasn’t worth eating. (Ever turned your nose up at airplane food? Same idea.) Sometimes I would bring my own food, and it’s gotten a lot easier to use a delivery service to get food from a safer (and often tastier) place. Or sometimes I couldn’t change the venue and there were supposedly safe options, but then the waiter did something that indicated it was likely not safe for me (e.g. saying “oh, just take the bread off your plate, no big deal”). That’s pretty much an automatic “do not eat here, it’s not safe” red flag being waved in my face.

It’s not fun to not get to eat or not get to do what everyone else around you is doing. I get it. Trust me, I do.

But do you know what is even LESS fun than feeling awkward? Getting glutened. Within minutes, feeling your chest tighten and getting abdominal cramps (that are like getting a “stitch in your side”, but all the way across your abdomen, and unrelenting for 30 minutes) that make you think you should go to the ER. Days of fatigue, brain fog and sore abdominal muscles. Knowing that you’ve increased the chances of tears in your small intestines and increased the risk of various types of cancers. All because of a speck of a crumb that found its way into your food.

So I make awkward choices. Sometimes I face teasing, and occasionally outright bullying, although thankfully that has been rare. And I’ve survived these choices.

I’ve gotten better over time, researching venues and making recommendations about safe places for me to eat. 99% of the time, people have zero problem going to the places I recommend. They want me to be safe and happy, they don’t really care what they eat, they’d rather have my (happy) company than to go someplace without me. (And if your  friends/colleagues/family members don’t care that much about you…maybe this will give you some food for thought.) I can’t always find safe GF options, so I also plan ahead and pack tasty snacks or food options, eat in advance, or plan to eat afterward.

And when that’s not possible, I make the choice to do the “awkward” but safe thing for me.

So in a COVID-19 or similar pandemic, I want you to know that you have choices. I’ve read a few stories from folks online who have shared regrets that they felt “peer pressure” to go eat at a conference, inside, because that’s what their friends or colleagues were doing. And they got COVID-19. Which doesn’t sound fun in the short run (being sick, getting stuck in foreign countries or strange cities, having to disrupt the lives of everyone around you, struggling to not infect your loved ones, being stuck without child care), nor the long run (risks of long COVID, or risks of additional conditions that can occur following COVID).

If you need ideas, here are some you can consider:

  • Pick an outside venue.
  • Get takeout food and go eat outside somewhere.
  • If you are inside, ensure good ventilation (sit by windows, open the windows). If you’re unsure the ventilation is good enough, you can bring a CO2 meter* to measure just how stale the air is. If you have a choice, sit somewhere quieter and further away from others, so you don’t have to yell in each other’s faces to be heard.
  • If the ventilation isn’t great, or you’re in a loud and/or crowded venue talking face to face with people who haven’t recently tested, you might want to stay masked except for when you are eating or drinking. Then put your mask back on. Limit the time you are exposed to the indoor air that everyone else’s been breathing.
  • If you are inside a poorly ventilated, loud, and/or crowded space, or otherwise consider the risks to be too high for your comfort, you can leave your N95 mask on the whole time – you don’t have to eat just because everyone else is eating unmasked!

I get it. It’s hard, it’s awkward, and peer pressure is real. But you do have choices you can make, and it gets easier when you think about your choices in advance and mitigate or decide how you’ll handle such a situation.

I hope this has given you food for thought about what choices you could make if you’re worried about such situations, and know that there are many others out there making similar choices, whether it’s because of COVID-19 or because of things like celiac disease, food allergies, or other dietary restrictions for health reasons.

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Note: this is the CO2 monitor we bought (amazon affiliate link). It’s pricey, but we’ve definitely put it to use on planes and at meetings and feel like it is a worthwhile tool.

Risk calculation in pandemic and post-pandemic era for assessing travel opportunities

by Dana Lewis

As someone who’s frequently been asked to travel and give talks over the last decade or so, I’ve had an evolving calculation to determine when a trip is “worth” it. This includes assessing financial cost to me (whether accommodations and travel are paid for; whether my time being paid for or not); opportunity cost (if I do this trip, what can’t I do that I would be doing otherwise); relationship and family cost (time away from family); as well as wellness cost (such as jet lag and physical demands of travel during and after a trip).

It’s clearly not a straightforward calculation and it has changed over time. Some things can influence this calculation – for example, if someone is willing to pay for my time and indicate that they value my presence by doing so, I may factor that in as a higher signal of whether this trip might be “worth” it, among the other variables. (And I’ve written previously about all the reasons why people, including patients, should be paid for their time in giving talks and traveling for conferences, meetings, and events, and I still believe this. However, there *are* exceptions that I personally am willing to make regarding payment for my time, but those are unique to me, my situation, my choices, the type of organization or meeting, etc. and I make these exceptions on a case by case basis.)

The pandemic also changed this calculation by adding new variables.

After February 2020, I did not complete any travel for work (including giving talks, attending conferences, etc.) for the rest of the year or in 2021. I was an early voice for interventions for COVID-19 beginning in February 2020, in part because of the risk to the community around me as well as to the risk to myself as someone who has type 1 diabetes. I received a few in-person speaking invitations that I turned down directly, or encouraged them to evolve into virtual events so that I and others could participate safely.

Now, though, it’s becoming clear (sadly) that COVID-19 will be endemic, and although I am not ready to go back to in-person events, many people are, and conferences are increasingly returning and planning to return to in-person physical events moving forward.

And as a result, I see and experience a mismatch in risk tolerance and risk calculations among different groups of people.

For some people, the risk calculation is as simple as considering, “am I fully vaccinated? Then I’m good to go and attend any events and follow whatever regulation or lack of regulation exists for that conference.”

For other people, it is a more complex risk calculation. It may take into account whether they are someone with a condition or chronic illness that puts them at higher risk for severe outcomes, even with COVID-19 vaccination. It may take into account a loved one or family situation where someone close to them is at higher risk. It may take into account that there are different rates of COVID-19 cases, and different rates of vaccination, at their home location compared to the conference location. It may take into account the risk of disruption to their lives if they were to acquire COVID-19 during travel or at the conference and be forced to remain in a different city or country, sick and alone, until they were cleared to travel. That also includes the financial disruption of paying for lodging, changed travel plans, as well as any disruption to home life where childcare or other plans were upended at home while the person was stuck elsewhere.

It is, therefore, much more complicated than “am I vaccinated?” and “does the conference have a protocol?”.

There’s no straightforward answer; there may not be the same answer for everyone in the same situation. Therefore people are also likely to have different risk calculations to make and may arrive at a different decision than you might want them to make.

I hope we can all expand our awareness and recognize that different people have different situations and that the COVID-19 pandemic – still – affects all of us very differently.

How to deal with wildfire smoke and air quality issues during COVID-19

by Dana Lewis

2020. What a year. We’ve been social distancing since late February and being very careful in terms of minimizing interactions even with family, for months. We haven’t traveled, we haven’t gone out to eat, and we basically only go out to get exercise (with a mask when it’s on hiking trails/around anyone) or Scott goes to the grocery store (n95 masked). We’ve been working on CoEpi (see CoEpi.org – an open source exposure notification app based on symptom reports) and staying on top of the scientific literature around COVID-19, regarding NPIs like distancing and masking; at-home diagnostics like temperature and pulse oximetry monitoring, prophylactics and treatments like zinc, quercetine, and even MMR vaccines; and the impact of ventilation and air quality on COVID-19 transmission and susceptibility.

And we live in Washington, so the focus on air quality got very real very quickly during this year’s wildfire season, where we had wildfires across the state of Washington, then got pummeled for over a week with hazardous levels of wildfire smoke coming up from Oregon and California to cover our existing smoke layer. But, one of our DIY air quality hacks for COVID-19 gave us a head start on air quality improvements for smoke-laden air, which I’ll describe below.

Here are various things we’ve gotten and have been using in our personal attempts to thwart COVID-19:

  • Finger pulse oximeter.
    • Just about any cheap pulse oximeter you can find is fine. The goal is to get an idea of your normal baseline oxygen rates. If you dip low, that might be a reason to go to urgent care or the ER or at least talk to your doctor about it. For me, I am typically 98-99% (mine doesn’t read higher than 99%), and my personal plan would be to talk to a healthcare provider if I was sick and started dropping below 94%.
  • Thermometer
    • Use any thermometer that you’ll actually use. I have previously used a no-touch thermometer that could read foreheads but found it varied widely and inconsistently, so I went back to an under the tongue thermometer and took my temperature for several months at different times to figure out my baselines. If sick or you have a suspected exposure, it’s good to be checking at different times of the day (people often have lower temps in the morning than in the evening, so knowing your daily differences may help you evaluate if you’re elevated for you or not).
    • Note: women with menstrual cycles may have changes related to this; such as lower baseline temps at the start of the cycle and having a temperature upswing around or after the mid-point in their cycle. But not all do. Also, certain medications or birth controls can impact basal temperatures, so be aware of that.
  • Originally, n95 masks with outlet valves.
    • Note: n95 masks with valves cannot be used by medical professionals, because the valves make them less effective for protecting others. (So don’t freak out at people who had a box of valved n95 masks from previous wildfire smoke seasons, as we did. Ahem.) 
    • We had a box we bought after previous years’ wildfire smoke, and they work well for us (in low-risk non-medical settings) for repeated use. They’re Scott’s go-to choice. If you’re in a setting where the outlet valve matters (indoors in a doctor’s/medical setting, or on a plane), you can easily pop a surgical/procedure mask over the valve to block the valve to protect others from your exhaust, while still getting good n95-level protection for yourself.
    • They were out of stock since February, but given the focus on n95 without valves for medical PPE, there have been a few boxes of n95 masks with outlet valves showing up online at silly prices ($7 per mask or so). But, kn95’s are a cheaper per mask option that are generally more available – see below.
    • (June 2021 note – they are back to reasonable prices, in the $1-2 range per mask on Amazon, and available again.)
  • kn95 masks.
    • kn95 masks are a different standard than US-rated n95; but they both block 95% of tiny (0.3 micron) particles. For non-medical usage, we consider them equivalent. But like n95, the fit is key.
    • We originally bought these kn95s, but the ear loops were quite big on me. (See below for options if this is the case on any you get.) They aren’t as hardy as the n95s with valves (above); the straps have broken off, tearing the mask, after about 4-5 long wears. That’s still worth it for them being $2-3 each (depending on how many you buy at a time) for me, but I’d always pack a spare mask (of any kind) just in case.
      • Option one to adjust ear loops: I loop them over my ponytail, making them head loops. This has been my favorite kn95 option because I get a great fit and a tight seal with this method.
      • Option two to adjust ear loops: tie knots in the ear loops
      • Option three to adjust ear loops: use things like this to tighten the ear loops
    • We also got a set of these kn95s. They don’t fit quite as well in terms of a tight face fit, but these actually work as ear loops (as designed), and I was able to wear this inside the house on the worst day of air quality.
  • Box fan with a filter to reduce COVID-19 particles in the air:
    • We read this story about using an existing AC air furnace filter on a box fan to help reduce the number of COVID-19 particles in the air. We already had a box fan, so we took one of our spare 20×20 filters and popped it on. I’m allergic to dust, cats (which we just got), trees, grass, etc, so I knew it would also help with regular allergens. There are different levels of filter – all the way up to HEPA filters – but we had MERV 12 so that’s what we used.
  • Phone/object UV sanitizer
    • We got a PhoneSoap Pro (in lavender, but there are other colors). Phones are germy, and being able to pop the phone in (plus keys or any other objects like credit cards or insurance cards that might have been handled by another human) to disinfect has been nice to have.
    • The Pro is done sanitizing in 5 minutes, vs the regular one takes 10 minutes. It’s not quite 2x the price as the non-pro, but I’ve found it to be worthwhile because otherwise, I would be impatient to get my phone back out. I usually pop my phone in it when I get home from my walk, and by the time I’m done washing my hands and all the steps of getting home, the phone is about or already done being sanitized.
  • Bonus (but not as useful to everyone as the above, and pricey): Oura ring
    • Scott and I also both got Oura rings. They are pricey, but every morning when we wake up we can see our lowest resting heart rate (RHR), heart rate variability (HRV), temperature deviations, and respiratory rate (RR). There have been studies showing that HRV, RHR, overnight temperature, and RR changes happen early in COVID-19 and other infections, which can give an early warning sign that you might be getting sick with something. That can be a good early warning sign (before you get to the point of being symptomatic and highly infectious) that you need to mask up and work from home/social distance/not interact with other people if you can help it. I find the data soothing, as I am used to using a lot of diabetes data on a daily and real-time basis (see also: invented an open source artificial pancreas). Due to price and level of interest in self-tracking data, this may not be a great tool for everyone.
    • Note this doesn’t tell you your temperature in real time, or present absolute values, but it’s helpful to see, and get warnings about, any concerning trends in your body temperature data. I’ve seen several anecdotal reports of this being used for early detection of COVID-19 infection and various types of relapses experienced by long-haulers.

And here are some things we’ve added to battle air quality during wildfire smoke season:

  • We were already running a box fan with a filter (see above for more details) for COVID-19 and allergen reduction; so we kept running it on high speed for smoke reduction.
    • Basic steps: get box fan, get a filter, and duct tape or strap it on. Doesn’t have to be cute, but it will help.
    • I run this on high speed during the day in my bedroom, and then on low speed overnight or sleep with earplugs in.
  • We already had a small air purifier for allergens, which we also kept running on high. This one hangs out in our guest bedroom/my office.
  • We caved and got a new, bigger air purifier, since we expect future years to be equally and unfortunately as smoky. This is the new air purifier we got. (Scott chose the 280i version that claims to cover 279 sq. ft.). It’s expensive, but given how miserable I was even inside the house with decent air quality thanks to my box fan and filter, little purifier, and our A/C filtered air… I consider it to be worth the investment.
    • We plugged it in and validated that with our A/C-filtered air combined with my little air purifier and the box fan with filter running on high, we already had ‘good’ air quality (but not excellent). We also stuck it out in the hallway to see what the hallway air quality was running – around 125 ug/m^3 – yikes. Turns out that was almost as high as the outside air, which is I’ve had to wear a kn95 mask even to walk hallway laps, and why my eyes are irritated. example air quality difference between hallway and our kitchen. hallway is much higher.
  • Check your other filters while you’re on air quality monitoring alert. We found our A/C intake duct vent had not had the air filter changed since we moved in over a year ago… and turns out it’s a non-standard size and had a hand-cut stuffed in there, so we ordered a correctly sized one for the vent, and taped a different one over the outside in the interim.
  • The other thing to fight the smoke is having n95 with valves or kn95 masks to wear when we have to go outside, or if it gets particularly bad inside. Our previous strategy was to have several on hand for wildfire season, and we’ll continue to do this. (See above in the COVID-19 section for descriptions in more detail about different kinds of masks we’ve tried.)
  • 2022 update: I got a mini personal air purifier to try for travel (to help reduce risk of COVID-19 in addition to all other precautions like staying masked on planes and indoor spaces), but it also turned out to be beneficial inside during the worst of our 2022 wildfire smoke season. I had a slightly scratchy throat even with two box fans and two different air purifiers inside; but keeping this individual one plugged in and pointed at my face overnight eliminated me waking up with a scratchy throat. That’s great for wildfire smoke, and also shows that there is some efficacy to this fan for it’s intended purpose, which is improving air around my face during travel in inside spaces for COVID-19 and other disease prevention.

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Wildfires, their smoke, and COVID-19 combined is a bit of a mess for our health. Stay inside when you can, wear masks when you’re around other people outside your household that you have to share air with, wash your hands, and good luck.