This Huberman Lab podcast interviews Dr. Roger Seheult, a pulmonologist and sleep medicine specialist, about preventing and treating colds, flus, and other viruses, including long COVID. The discussion centers around the "NEW START" mnemonic for health (Nutrition, Exercise, Water, Sunlight, Temperance, Air, Rest, Trust), with a detailed exploration of sunlight's impact on mitochondrial function and melatonin production. Dr. Seheult highlights studies showing sunlight's protective effects against influenza and COVID-19, emphasizing the importance of daily sunlight exposure (15-20 minutes) even on cloudy days. The benefits of N-acetylcysteine (NAC) for reducing flu symptoms and supporting liver health are also discussed, along with the importance of darkness at night for optimal sleep and health. Listeners gain actionable advice on improving immune function and recovering from illness.