Winter Sickness, Nasal Breathing & Cold Exposure Protocols
Summary
This AMA episode addresses why colds and flus are more prevalent during winter months, examining the roles of indoor proximity, dry air, and nasal passage health. Huberman also introduces the topic of deliberate breathing techniques (including Wim Hof breathing) and cold exposure as tools that may help prevent — or worsen — illness depending on timing and context.
Key Takeaways
- Physical proximity is the primary driver of cold and flu transmission — the closer you are to someone who is sneezing or coughing, the higher your risk.
- Anyone actively sneezing or coughing from a cold or flu is still contagious, regardless of claims about being “early” or “late” in illness.
- Dry indoor air from heating systems damages the nasal mucosal lining, reducing its ability to trap and neutralize incoming pathogens.
- Nasal breathing provides a critical physical defense against viral, bacterial, and fungal infections through nasal hairs, mucus, and the local microbiome.
- Mouth breathers show significantly higher prevalence of respiratory illness and allergies compared to nasal breathers.
- Using an air humidifier, especially at night, helps maintain healthy nasal passages and improves resistance to infection.
- Core body temperature is linked to susceptibility — warming up after cold outdoor exposure (hot shower, sauna) may reduce infection risk.
- Fever is an immune adaptation designed to destroy viruses; suppressing it may allow the pathogen to proliferate more easily.
- Cyclic hyperventilation breathing and deliberate cold exposure may prevent infection but could be counterproductive if you are already sick (to be covered in full in a future episode).
Detailed Notes
Why More Colds & Flus Occur in Winter
Winter months bring three interconnected conditions that drive increased illness:
- Shorter days → less sunlight exposure
- Colder outdoor temperatures → people move indoors
- More time indoors → increased physical proximity to infected individuals
Research confirms this is not a myth — there is a genuine greater prevalence of colds and flus during winter months in most regions of the world.
Transmission & Physical Proximity
- Studies show a direct dose-response relationship between physical distance and transmission risk.
- Risk increases with: shared indoor air, kissing, hugging, handshakes (especially without hand-washing after nose-wiping).
- Cold/flu virus can survive on skin and be transmitted via touch.
- Outdoor sneezing carries slightly lower transmission risk than indoor sneezing at the same distance, but proximity still matters outdoors.
- Sneezing into the elbow (not the hand) is recommended to reduce surface contamination.
Dry Air & Nasal Passage Health
- Heated indoor air is dry air, which dries out the nasal and oral passages.
- Cold outdoor air is also dry; exercising outdoors in winter can similarly dry nasal passages.
- The nasal mucosal lining acts as the primary physical defense against pathogens:
- Nasal hairs trap particles
- Mucus physically captures viruses, bacteria, and fungi
- A thriving local microbiome neutralizes many threats
Protocol: Use an air humidifier at home, especially in the bedroom during sleep, to maintain nasal passage integrity.
Nasal vs. Mouth Breathing
- Nasal breathing should be the default whenever not eating, speaking, or exercising at high intensity.
- A key referenced paper: “Association of oral breathing with dental malocclusions and general health in children” — findings include:
- Oral breathing is associated with significantly higher prevalence of allergies
- Mouth breathers are significantly more likely to get sick and to require medication for illness
- Nasal breathing is superior for dental health, facial development, and respiratory defense.
Core Body Temperature & Fever
- Being chilled may increase susceptibility to cold and flu; warming up after cold outdoor exposure (hot shower, steam room, sauna) is recommended.
- Fever is a deliberate immune mechanism — the body raises temperature to destroy viruses.
- Suppressing fever with medication allows the pathogen to proliferate more easily.
- However, very high fevers are dangerous to the brain and body, so context matters.
Wim Hof Breathing & Cold Exposure (Preview Only)
This section was introduced but not completed in the public portion of the episode. Topics to be covered include:
- How cyclic hyperventilation / Wim Hof breathing may prevent infection
- How deliberate cold exposure may be used to offset bacterial or viral infection
- Why both interventions may be contraindicated if you are already actively sick