Summary
This premium AMA episode focuses on why colds and flus are more prevalent during winter months and practical strategies for prevention. Huberman explains three key factors: increased indoor proximity during cold weather facilitating viral transmission, heated indoor air drying out the nasal mucosal lining (a primary defense barrier against pathogens), and reduced sunlight exposure weakening immune function. He emphasizes that the nasal passages contain physical barriers (hairs, mucus, microbiome) that actively trap and combat viruses, and that nasal breathing is significantly more protective than mouth breathing against respiratory infections.
Huberman provides evidence-based protocols for cold and flu prevention: maintaining nasal breathing whenever possible, using air humidifiers especially during sleep, getting afternoon sunlight to support immune function, rewarming after cold exposure with hot showers or sauna rather than staying chilled, and understanding that fever is an adaptive immune response that should not always be suppressed with medication. The episode also previews a discussion on Wim Hof breathing and its relationship to stress resilience and immune function, noting the distinction between deliberate cold exposure protocols and the risk of getting chilled during winter.
Key Points
- Winter cold and flu increases are driven primarily by closer indoor proximity, dried nasal passages from heated air, and reduced sunlight exposure rather than cold temperature alone
- Nasal breathing is significantly more protective against respiratory infections than mouth breathing; the nasal mucosal lining contains hairs, mucus, and microbiome that trap pathogens
- Air humidifiers, especially during sleep, help maintain the integrity of nasal mucosal barriers that are your first line of defense against viral infections
- Fever is an adaptive immune response designed to destroy viruses; suppressing low-grade fevers with medication may allow viruses to proliferate more readily
- Physical proximity is the strongest predictor of cold and flu transmission, with a direct relationship between distance and infection probability
- Rewarming after cold outdoor exposure through hot showers or sauna may help prevent illness by maintaining core body temperature, which supports immune function
- People who are sneezing or coughing from a cold or flu are contagious regardless of where they are in the illness timeline, despite common claims otherwise
Key Moments
Why you get sick in winter: nasal breathing, humidity, and cold/flu defense
Mouth breathers get significantly more colds and flu. The nasal passages' hairs, mucus, and microbiome form a critical defense. Humidifying indoor air and nasal breathing are key winter protections.
"Also, people who tend to breathe through their mouth more tend to get more colds and flus. Now, you might think that's the same thing or just two sides of the same coin, but actually it's not."
