November 8th, 2026
IN PARTNERSHIP WITH AIRDOCTOR
It’s Sunday. Flu is running higher than usual for this time of year, and Thanksgiving is 18 days away. This week’s deep dive is a simple plan for getting through winter without losing a week to the couch.
Last week’s deep dive: Train Like Rocky This Winter
DEEP DIVE
Get Through Winter Without Getting Sick
Between 2007 and 2011, researchers recruited 164 healthy volunteers around Pittsburgh for a strange job.
They wore a sleep sensor for a week. Then they checked into a hotel, took a cold virus through nose drops and stayed for a week while scientists collected their mucus every day.
Same hotel. Same virus. Some got sick, and some didn’t.
“Short sleep was more important than any other factor in predicting subjects’ likelihood of catching cold,” said Aric Prather, the UCSF researcher who led the study. People who slept under six hours a night were 4.2 times more likely to catch it than people who slept more than seven. That held after accounting for age, stress, income and smoking.
You can’t control who coughs near you this winter. You can control a lot at home: your air, your sleep, what you drink and what you eat.
Why it matters: US adults catch two to three colds a year on average, and kids often catch more. Colds are one of the most common reasons people miss work and school.
Why now: How fast is flu moving? The CDC estimates at least 1.7 million illnesses so far this season , up from 1 million a week earlier , and says activity is higher than usual for this time of year.
The plan:
- Fix your air before the windows stay shut.
- Protect 7 hours of sleep.
- Drink more while the heat is running.
- Eat something fermented most days.
- Move most days and wash up.
More below.
STEP 1: AIR
Fix the Air You’re Stuck In
How much can better air matter? In a CDC study of 169 Georgia elementary schools in late 2020, COVID rates ran 35% lower in schools that brought in outside air with open windows, doors or fans. In schools that added HEPA filters, they ran 48% lower.
It’s worth noting: that was one virus, in schools. Homes are different. The logic carries over: fewer particles in the air, fewer chances to breathe one in.
Dry air is the other problem. Yale’s Akiko Iwasaki and her team kept mice in low humidity before exposing them to flu. Their airways repaired themselves and cleared germs less well, and they fared worse than mice kept at 50%.
This week:
- Put a HEPA purifier where you sleep, the room where you spend the most hours.
- Crack a window for a few minutes on milder days.
- Check your humidity. Mayo Clinic says 30% to 50% . Some flu researchers say 40% to 60% . Aim for the overlap: 40% to 50%.
- Keep the humidifier clean. Mayo says to change the water daily and clean it every three days.
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STEP 2: SLEEP
Protect the 7 Hours
One in five Americans gets less than six hours on a typical work night, according to a 2013 survey . That’s the sleep range that caught more colds in Pittsburgh.
- Pick your wake-up time first, then count back 7.5 hours. That’s your bedtime.
- Set an alarm for bed. You already have one for the morning.
- Keep the room cool and dark.
- Leave the phone outside the bedroom for the last 20 minutes of the day.
STEP 3: WATER
Drink More Once the Heat Comes On
Cold weather can mute your thirst by up to 40% , as we wrote last Sunday. Now add months of dry, heated air.
And if a cold gets you anyway, fluids top Mayo Clinic’s list of what works . Water, juice or warm lemon water with honey help loosen congestion and keep you from getting dehydrated. (Honey may help coughs too, in adults and kids older than 1.) Mayo says to skip alcohol, coffee and caffeinated sodas until you’re better.
- Drink a glass before the coffee.
- Keep one by the bed, where the heat runs all night.
- Try a mug of lemon and honey in place of the second glass of wine.
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The Easiest Way to Drink More This Winter
Most of us know we should drink more, and plain water gets old by about week two .
Vita Coco Original Coconut Water makes it easier to stick with. It naturally contains electrolytes like potassium , and it’s a lighter way to refresh with the heat running all day:
- First thing in the morning, before the coffee.
- After a workout or a long, cold dog walk.
- Anytime, in place of the afternoon soda.
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STEP 4: GUT
Eat Something Alive
In 2021, Stanford researchers put 36 healthy adults on one of two diets for 10 weeks. One group ate more fiber. The other ate more fermented foods: yogurt, kefir, kimchi, kombucha.
The researchers expected fiber to do more. Instead, 19 inflammatory proteins fell in the fermented-food group and none fell in the fiber group. Gut microbes got more diverse too, with stronger effects from bigger servings.
The caveat: 36 people is a small study, and it didn’t track who caught a cold. Keep eating your fiber.
- Breakfast: yogurt or kefir. Look for live cultures on the label.
- Dinner: a forkful of kimchi or sauerkraut.
- Afternoon: kombucha in place of a soda.
THE WINTER KIT
8 Things to Have Before Someone Starts Coughing
For the air:
- Levoit top-fill humidifier : a 2.5-liter cool-mist model that runs quietly at 25 decibels and shuts itself off when it’s empty.
- TempPro TP50 humidity gauge : about $11, with more than 156,000 ratings. It tells you where you stand on that 40% to 50%.
For sleep:
- High Frequency Highway Frequency Headphones (Partner*): bone-conduction headphones that rest on your cheekbones and pair sound with vibration you can feel, built for calm, meditation and sleep preparation. Code HOLIDAYS saves you 15%.
- Manta Original sleep mask : a blackout mask with adjustable eye cups that keep pressure off your eyes.
For the gut:
- Cocojune coconut yogurt (Partner*): plant-based yogurt made from organic coconuts, with probiotic cultures.
For the first sniffle:
- Braun ThermoScan 7 : an ear thermometer that works on adults and babies.
- iHealth 3-in-1 rapid test : four at-home tests for flu A, flu B and COVID.
- NeilMed Sinus Rinse kit : a squeeze bottle and 50 saline packets for a stuffy nose. Use distilled or boiled water.
STEP 5: THE EASY STUFF
Move and Wash Up
Move most days. Researchers followed 1,002 adults for 12 weeks through fall and winter. People doing aerobic exercise at least five days a week had 43% fewer sick days than people who were largely sedentary. It’s a link rather than proof, and it’s a good reason to keep walking in the cold.
Wash your hands. Teaching people to wash cuts colds and other respiratory illnesses by 16% to 21% , the CDC says. Mayo Clinic’s Dr. Gregory Poland shows the right way in about a minute (w/video): scrub for at least 20 seconds, including your wrists, between your fingers and under your nails.
And the kids? They’ll bring something home anyway. UCSF immunologist Max Krummel explained why on Huberman Lab, in an episode we summarized : nearly every bug is new to them, and their immune systems clear most of them fast. Yours will probably bounce back before you do.
OUR TAKEAWAY
Stack the Odds
All 164 people in that Pittsburgh hotel got the same virus. How they slept the week before changed their odds.
You’ll probably still catch something this winter. A cleaner bedroom, seven hours, a full glass, a spoon of yogurt, a walk in the cold: each one is small, and they stack.
Start tonight.
GO DEEPER
- Why short sleepers catch more colds (UCSF)
- How dry air weakens your airways (PNAS)
- The fermented-food trial (Stanford Medicine)
- Cold remedies: what works and what doesn’t (Mayo Clinic)
- How your immune system works, with Dr. Max Krummel
The 1% Better Team